Extensive changes that _should_ fix the socket buffering problems,
[u/mdw/putty] / terminal.c
index 444f243..87c151e 100644 (file)
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <ctype.h>
 
+#include <time.h>
+#include <assert.h>
 #include "putty.h"
+#include "tree234.h"
+
+#define VT52_PLUS
+
+#define CL_ANSIMIN     0x0001         /* Codes in all ANSI like terminals. */
+#define CL_VT100       0x0002         /* VT100 */
+#define CL_VT100AVO    0x0004         /* VT100 +AVO; 132x24 (not 132x14) & attrs */
+#define CL_VT102       0x0008         /* VT102 */
+#define CL_VT220       0x0010         /* VT220 */
+#define CL_VT320       0x0020         /* VT320 */
+#define CL_VT420       0x0040         /* VT420 */
+#define CL_VT510       0x0080         /* VT510, NB VT510 includes ANSI */
+#define CL_VT340TEXT   0x0100         /* VT340 extensions that appear in the VT420 */
+#define CL_SCOANSI     0x1000         /* SCOANSI not in ANSIMIN. */
+#define CL_ANSI                0x2000         /* ANSI ECMA-48 not in the VT100..VT420 */
+#define CL_OTHER       0x4000         /* Others, Xterm, linux, putty, dunno, etc */
+
+#define TM_VT100       (CL_ANSIMIN|CL_VT100)
+#define TM_VT100AVO    (TM_VT100|CL_VT100AVO)
+#define TM_VT102       (TM_VT100AVO|CL_VT102)
+#define TM_VT220       (TM_VT102|CL_VT220)
+#define TM_VTXXX       (TM_VT220|CL_VT340TEXT|CL_VT510|CL_VT420|CL_VT320)
+#define TM_SCOANSI     (CL_ANSIMIN|CL_SCOANSI)
+
+#define TM_PUTTY       (0xFFFF)
+
+#define compatibility(x) \
+    if ( ((CL_##x)&compatibility_level) == 0 ) {       \
+       termstate=TOPLEVEL;                             \
+       break;                                          \
+    }
+#define compatibility2(x,y) \
+    if ( ((CL_##x|CL_##y)&compatibility_level) == 0 ) { \
+       termstate=TOPLEVEL;                             \
+       break;                                          \
+    }
+
+#define has_compat(x) ( ((CL_##x)&compatibility_level) != 0 )
+
+static int compatibility_level = TM_PUTTY;
+
+static tree234 *scrollback;           /* lines scrolled off top of screen */
+static tree234 *screen;                       /* lines on primary screen */
+static tree234 *alt_screen;           /* lines on alternate screen */
+static int disptop;                   /* distance scrolled back (0 or -ve) */
 
-static unsigned long *text;           /* buffer of text on terminal screen */
-static unsigned long *scrtop;         /* top of working screen */
-static unsigned long *disptop;        /* top of displayed screen */
-static unsigned long *sbtop;          /* top of scrollback */
 static unsigned long *cpos;           /* cursor position (convenience) */
+
 static unsigned long *disptext;               /* buffer of text on real screen */
-static unsigned long *wanttext;               /* buffer of text we want on screen */
-static unsigned long *alttext;        /* buffer of text on alt. screen */
+static unsigned long *dispcurs;               /* location of cursor on real screen */
+static unsigned long curstype;        /* type of cursor on real screen */
 
-static unsigned char *selspace;               /* buffer for building selections in */
+#define VBELL_TIMEOUT 100             /* millisecond len of visual bell */
 
-#define TSIZE (sizeof(*text))
-#define fix_cpos  do { cpos = scrtop + curs_y * (cols+1) + curs_x; } while(0)
+struct beeptime {
+    struct beeptime *next;
+    long ticks;
+};
+static struct beeptime *beephead, *beeptail;
+int nbeeps;
+int beep_overloaded;
+long lastbeep;
 
-static unsigned long curr_attr, save_attr;
+#define TSIZE (sizeof(unsigned long))
+#define fix_cpos do { cpos = lineptr(curs.y) + curs.x; } while(0)
 
-static int curs_x, curs_y;            /* cursor */
-static int save_x, save_y;            /* saved cursor position */
+static unsigned long curr_attr, save_attr;
+static unsigned long erase_char = ERASE_CHAR;
+
+typedef struct {
+    int y, x;
+} pos;
+#define poslt(p1,p2) ( (p1).y < (p2).y || ( (p1).y == (p2).y && (p1).x < (p2).x ) )
+#define posle(p1,p2) ( (p1).y < (p2).y || ( (p1).y == (p2).y && (p1).x <= (p2).x ) )
+#define poseq(p1,p2) ( (p1).y == (p2).y && (p1).x == (p2).x )
+#define posdiff(p1,p2) ( ((p1).y - (p2).y) * (cols+1) + (p1).x - (p2).x )
+#define incpos(p) ( (p).x == cols ? ((p).x = 0, (p).y++, 1) : ((p).x++, 0) )
+#define decpos(p) ( (p).x == 0 ? ((p).x = cols, (p).y--, 1) : ((p).x--, 0) )
+
+static pos curs;                      /* cursor */
+static pos savecurs;                  /* saved cursor position */
 static int marg_t, marg_b;            /* scroll margins */
 static int dec_om;                    /* DEC origin mode flag */
 static int wrap, wrapnext;            /* wrap flags */
 static int insert;                    /* insert-mode flag */
 static int cset;                      /* 0 or 1: which char set */
 static int save_cset, save_csattr;     /* saved with cursor position */
+static int save_utf;                  /* saved with cursor position */
 static int rvideo;                    /* global reverse video flag */
+static int rvbell_timeout;            /* for ESC[?5hESC[?5l vbell */
+static int cursor_on;                 /* cursor enabled flag */
+static int reset_132;                 /* Flag ESC c resets to 80 cols */
+static int use_bce;                   /* Use Background coloured erase */
+static int blinker;                   /* When blinking is the cursor on ? */
+static int tblinker;                  /* When the blinking text is on */
+static int blink_is_real;             /* Actually blink blinking text */
+static int term_echoing;              /* Does terminal want local echo? */
+static int term_editing;              /* Does terminal want local edit? */
+static int sco_acs, save_sco_acs;      /* CSI 10,11,12m -> OEM charset */
+static int vt52_bold;                 /* Force bold on non-bold colours */
+static int utf_state;                 /* Is there a pending UTF-8 character */
+static int utf_char;                  /* and what is it so far. */
+static int utf_size;                  /* The size of the UTF character. */
+
+static int xterm_mouse;                       /* send mouse messages to app */
 
 static unsigned long cset_attr[2];
 
 /*
  * Saved settings on the alternate screen.
  */
-static int alt_x, alt_y, alt_om, alt_wrap, alt_wnext, alt_ins, alt_cset;
+static int alt_x, alt_y, alt_om, alt_wrap, alt_wnext, alt_ins, alt_cset, alt_sco_acs, alt_utf;
 static int alt_t, alt_b;
 static int alt_which;
 
 #define ARGS_MAX 32                   /* max # of esc sequence arguments */
-#define ARG_DEFAULT -1                /* if an arg isn't specified */
+#define ARG_DEFAULT                 /* if an arg isn't specified */
 #define def(a,d) ( (a) == ARG_DEFAULT ? (d) : (a) )
 static int esc_args[ARGS_MAX];
 static int esc_nargs;
 static int esc_query;
+#define ANSI(x,y)      ((x)+((y)<<8))
+#define ANSI_QUE(x)    ANSI(x,TRUE)
 
 #define OSC_STR_MAX 2048
 static int osc_strlen;
-static char osc_string[OSC_STR_MAX+1];
+static char osc_string[OSC_STR_MAX + 1];
 static int osc_w;
 
-static unsigned char *tabs;
-
-#define MAXNL 5
-static int nl_count;
+static char id_string[1024] = "\033[?6c";
 
-static int scroll_heuristic;
+static unsigned char *tabs;
 
 static enum {
     TOPLEVEL,
@@ -68,11 +149,13 @@ static enum {
 
     DO_CTRLS,
 
-    IGNORE_NEXT,
-    SET_GL, SET_GR,
     SEEN_OSC_P,
     OSC_STRING, OSC_MAYBE_ST,
-    SEEN_ESCHASH
+    VT52_ESC,
+    VT52_Y1,
+    VT52_Y2,
+    VT52_FG,
+    VT52_BG
 } termstate;
 
 static enum {
@@ -81,35 +164,109 @@ static enum {
 static enum {
     SM_CHAR, SM_WORD, SM_LINE
 } selmode;
-static unsigned long *selstart, *selend, *selanchor;
+static pos selstart, selend, selanchor;
 
 static short wordness[256] = {
-    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 01 */
-    0,1,2,1,1,1,1,1,1,1,1,1,1,2,2,2, 2,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1, /* 23 */
-    1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,1,1,1,1,2, /* 45 */
-    1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,1,1,1,1,1, /* 67 */
-    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 89 */
-    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* AB */
-    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2, /* CD */
-    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2, /* EF */
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0,           /* 01 */
+    0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    2, 2, 1, 1, 1, 1, 1, 1,           /* 23 */
+    1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    2, 2, 2, 1, 1, 1, 1, 2,           /* 45 */
+    1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    2, 2, 2, 1, 1, 1, 1, 1,           /* 67 */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,           /* 89 */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1,           /* AB */
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1,
+    2, 2, 2, 2, 2, 2, 2, 2,           /* CD */
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1,
+    2, 2, 2, 2, 2, 2, 2, 2,           /* EF */
 };
 
-static unsigned char sel_nl[] = SEL_NL;
+#define sel_nl_sz  (sizeof(sel_nl)/sizeof(wchar_t))
+static wchar_t sel_nl[] = SEL_NL;
+static wchar_t *paste_buffer = 0;
+static int paste_len, paste_pos, paste_hold;
 
 /*
  * Internal prototypes.
  */
-static void do_paint (Context, int);
-static void erase_lots (int, int, int);
-static void swap_screen (int);
-static void update_sbar (void);
-static void deselect (void);
+static void do_paint(Context, int);
+static void erase_lots(int, int, int);
+static void swap_screen(int);
+static void update_sbar(void);
+static void deselect(void);
+/* log session to file stuff ... */
+static FILE *lgfp = NULL;
+static void logtraffic(unsigned char c, int logmode);
+
+/*
+ * Resize a line to make it `cols' columns wide.
+ */
+unsigned long *resizeline(unsigned long *line, int cols)
+{
+    int i, oldlen;
+    unsigned long lineattrs;
+
+    if (line[0] != (unsigned long)cols) {
+       /*
+        * This line is the wrong length, which probably means it
+        * hasn't been accessed since a resize. Resize it now.
+        */
+       oldlen = line[0];
+       lineattrs = line[oldlen + 1];
+       line = srealloc(line, TSIZE * (2 + cols));
+       line[0] = cols;
+       for (i = oldlen; i < cols; i++)
+           line[i + 1] = ERASE_CHAR;
+       line[cols + 1] = lineattrs & LATTR_MODE;
+    }
+
+    return line;
+}
+
+/*
+ * Retrieve a line of the screen or of the scrollback, according to
+ * whether the y coordinate is non-negative or negative
+ * (respectively).
+ */
+unsigned long *lineptr(int y, int lineno)
+{
+    unsigned long *line, *newline;
+    tree234 *whichtree;
+    int treeindex;
+
+    if (y >= 0) {
+       whichtree = screen;
+       treeindex = y;
+    } else {
+       whichtree = scrollback;
+       treeindex = y + count234(scrollback);
+    }
+    line = index234(whichtree, treeindex);
+
+    /* We assume that we don't screw up and retrieve something out of range. */
+    assert(line != NULL);
+
+    newline = resizeline(line, cols);
+    if (newline != line) {
+       delpos234(whichtree, treeindex);
+       addpos234(whichtree, newline, treeindex);
+        line = newline;
+    }
+
+    return line + 1;
+}
 
+#define lineptr(x) lineptr(x,__LINE__)
 /*
  * Set up power-on settings for the terminal.
  */
-static void power_on(void) {
-    curs_x = curs_y = alt_x = alt_y = save_x = save_y = 0;
+static void power_on(void)
+{
+    curs.x = curs.y = alt_x = alt_y = savecurs.x = savecurs.y = 0;
     alt_t = marg_t = 0;
     if (rows != -1)
        alt_b = marg_b = rows - 1;
@@ -124,51 +281,64 @@ static void power_on(void) {
     alt_wnext = wrapnext = alt_ins = insert = FALSE;
     alt_wrap = wrap = cfg.wrap_mode;
     alt_cset = cset = 0;
+    alt_utf = utf = 0;
+    alt_sco_acs = sco_acs = 0;
     cset_attr[0] = cset_attr[1] = ATTR_ASCII;
     rvideo = 0;
+    in_vbell = FALSE;
+    cursor_on = 1;
+    big_cursor = 0;
     save_attr = curr_attr = ATTR_DEFAULT;
+    term_editing = term_echoing = FALSE;
+    ldisc_send(NULL, 0);              /* cause ldisc to notice changes */
     app_cursor_keys = cfg.app_cursor;
     app_keypad_keys = cfg.app_keypad;
+    use_bce = cfg.bce;
+    blink_is_real = cfg.blinktext;
+    erase_char = ERASE_CHAR;
     alt_which = 0;
     {
        int i;
        for (i = 0; i < 256; i++)
            wordness[i] = cfg.wordness[i];
     }
-    if (text) {
-       swap_screen (1);
-       erase_lots (FALSE, TRUE, TRUE);
-       swap_screen (0);
-       erase_lots (FALSE, TRUE, TRUE);
+    if (screen) {
+       swap_screen(1);
+       erase_lots(FALSE, TRUE, TRUE);
+       swap_screen(0);
+       erase_lots(FALSE, TRUE, TRUE);
     }
 }
 
 /*
  * Force a screen update.
  */
-void term_update(void) {
+void term_update(void)
+{
     Context ctx;
     ctx = get_ctx();
     if (ctx) {
-        if ( (seen_key_event && (unscroll_event & US_KEY)) &&
-            (seen_disp_event && (unscroll_event & US_DISP)) ) {
-           disptop = scrtop;
+       if (seen_disp_event)
+           update_sbar();
+       if ((seen_key_event && (cfg.scroll_on_key)) ||
+           (seen_disp_event && (cfg.scroll_on_disp))) {
+           disptop = 0;               /* return to main screen */
            seen_disp_event = seen_key_event = 0;
        }
-       do_paint (ctx, TRUE);
-       free_ctx (ctx);
-       nl_count = 0;
-       scroll_heuristic = 0;
+       do_paint(ctx, TRUE);
+       sys_cursor(curs.x, curs.y - disptop);
+       free_ctx(ctx);
     }
 }
 
 /*
  * Same as power_on(), but an external function.
  */
-void term_pwron(void) {
+void term_pwron(void)
+{
     power_on();
     fix_cpos;
-    disptop = scrtop;
+    disptop = 0;
     deselect();
     term_update();
 }
@@ -176,86 +346,130 @@ void term_pwron(void) {
 /*
  * Clear the scrollback.
  */
-void term_clrsb(void) {
-    disptop = sbtop = scrtop;
+void term_clrsb(void)
+{
+    unsigned long *line;
+    disptop = 0;
+    while ((line = delpos234(scrollback, 0)) != NULL) {
+       sfree(line);
+    }
     update_sbar();
 }
 
 /*
  * Initialise the terminal.
  */
-void term_init(void) {
-    text = sbtop = scrtop = disptop = cpos = NULL;
-    disptext = wanttext = NULL;
+void term_init(void)
+{
+    screen = alt_screen = scrollback = NULL;
+    disptop = 0;
+    disptext = dispcurs = NULL;
     tabs = NULL;
-    selspace = NULL;
     deselect();
     rows = cols = -1;
-    nl_count = 0;
     power_on();
+    beephead = beeptail = NULL;
+    nbeeps = 0;
+    lastbeep = FALSE;
+    beep_overloaded = FALSE;
 }
 
 /*
  * Set up the terminal for a given size.
  */
-void term_size(int newrows, int newcols, int newsavelines) {
-    unsigned long *newtext, *newdisp, *newwant, *newalt;
-    int i, j, crows, ccols;
+void term_size(int newrows, int newcols, int newsavelines)
+{
+    tree234 *newalt;
+    unsigned long *newdisp, *line;
+    int i, j;
+    int sblen;
+    int save_alt_which = alt_which;
 
     if (newrows == rows && newcols == cols && newsavelines == savelines)
        return;                        /* nothing to do */
 
+    deselect();
+    swap_screen(0);
+
     alt_t = marg_t = 0;
     alt_b = marg_b = newrows - 1;
 
-    newtext = smalloc ((newrows+newsavelines)*(newcols+1)*TSIZE);
-    disptop = newtext + newsavelines*(newcols+1);
-    for (i=0; i<(newrows+newsavelines)*(newcols+1); i++)
-       newtext[i] = ERASE_CHAR;
-    if (rows != -1) {
-       crows = rows + (scrtop - sbtop) / (cols+1);
-       if (crows > newrows+newsavelines)
-           crows = newrows+newsavelines;
-       ccols = (cols < newcols ? cols : newcols);
-       for (i=0; i<crows; i++) {
-           int oldidx = (rows + savelines - crows + i) * (cols+1);
-           int newidx = (newrows + newsavelines - crows + i) * (newcols+1);
-           for (j=0; j<ccols; j++)
-               newtext[newidx+j] = text[oldidx+j];
-           newtext[newidx+newcols] =
-               (cols == newcols ? text[oldidx+cols] : 0);
+    if (rows == -1) {
+       scrollback = newtree234(NULL);
+       screen = newtree234(NULL);
+       rows = 0;
+    }
+
+    /*
+     * Resize the screen and scrollback. We only need to shift
+     * lines around within our data structures, because lineptr()
+     * will take care of resizing each individual line if
+     * necessary. So:
+     * 
+     *  - If the new screen and the old screen differ in length, we
+     *    must shunt some lines in from the scrollback or out to
+     *    the scrollback.
+     * 
+     *  - If doing that fails to provide us with enough material to
+     *    fill the new screen (i.e. the number of rows needed in
+     *    the new screen exceeds the total number in the previous
+     *    screen+scrollback), we must invent some blank lines to
+     *    cover the gap.
+     * 
+     *  - Then, if the new scrollback length is less than the
+     *    amount of scrollback we actually have, we must throw some
+     *    away.
+     */
+    sblen = count234(scrollback);
+    /* Do this loop to expand the screen if newrows > rows */
+    for (i = rows; i < newrows; i++) {
+       if (sblen > 0) {
+           line = delpos234(scrollback, --sblen);
+       } else {
+           line = smalloc(TSIZE * (newcols + 2));
+           line[0] = newcols;
+           for (j = 0; j <= newcols; j++)
+               line[j + 1] = ERASE_CHAR;
        }
-       sbtop = disptop - (crows - newrows) * (newcols+1);
-       if (sbtop > disptop)
-           sbtop = disptop;
-    } else
-       sbtop = disptop;
-    scrtop = disptop;
-    sfree (text);
-    text = newtext;
+       addpos234(screen, line, 0);
+    }
+    /* Do this loop to shrink the screen if newrows < rows */
+    for (i = newrows; i < rows; i++) {
+       line = delpos234(screen, 0);
+       addpos234(scrollback, line, sblen++);
+    }
+    assert(count234(screen) == newrows);
+    while (sblen > newsavelines) {
+       line = delpos234(scrollback, 0);
+       sfree(line);
+       sblen--;
+    }
+    assert(count234(scrollback) <= newsavelines);
+    disptop = 0;
 
-    newdisp = smalloc (newrows*(newcols+1)*TSIZE);
-    for (i=0; i<newrows*(newcols+1); i++)
+    newdisp = smalloc(newrows * (newcols + 1) * TSIZE);
+    for (i = 0; i < newrows * (newcols + 1); i++)
        newdisp[i] = ATTR_INVALID;
-    sfree (disptext);
+    sfree(disptext);
     disptext = newdisp;
+    dispcurs = NULL;
+
+    newalt = newtree234(NULL);
+    for (i = 0; i < newrows; i++) {
+       line = smalloc(TSIZE * (newcols + 2));
+       line[0] = newcols;
+       for (j = 0; j <= newcols; j++)
+           line[j + 1] = erase_char;
+       addpos234(newalt, line, i);
+    }
+    if (alt_screen) {
+       while (NULL != (line = delpos234(alt_screen, 0)))
+           sfree(line);
+       freetree234(alt_screen);
+    }
+    alt_screen = newalt;
 
-    newwant = smalloc (newrows*(newcols+1)*TSIZE);
-    for (i=0; i<newrows*(newcols+1); i++)
-       newwant[i] = ATTR_INVALID;
-    sfree (wanttext);
-    wanttext = newwant;
-
-    newalt = smalloc (newrows*(newcols+1)*TSIZE);
-    for (i=0; i<newrows*(newcols+1); i++)
-       newalt[i] = ERASE_CHAR;
-    sfree (alttext);
-    alttext = newalt;
-
-    sfree (selspace);
-    selspace = smalloc ( (newrows+newsavelines) * (newcols+sizeof(sel_nl)) );
-
-    tabs = srealloc (tabs, newcols*sizeof(*tabs));
+    tabs = srealloc(tabs, newcols * sizeof(*tabs));
     {
        int i;
        for (i = (cols > 0 ? cols : 0); i < newcols; i++)
@@ -263,13 +477,13 @@ void term_size(int newrows, int newcols, int newsavelines) {
     }
 
     if (rows > 0)
-       curs_y += newrows - rows;
-    if (curs_y < 0)
-       curs_y = 0;
-    if (curs_y >= newrows)
-       curs_y = newrows-1;
-    if (curs_x >= newcols)
-       curs_x = newcols-1;
+       curs.y += newrows - rows;
+    if (curs.y < 0)
+       curs.y = 0;
+    if (curs.y >= newrows)
+       curs.y = newrows - 1;
+    if (curs.x >= newcols)
+       curs.x = newcols - 1;
     alt_x = alt_y = 0;
     wrapnext = alt_wnext = FALSE;
 
@@ -278,7 +492,8 @@ void term_size(int newrows, int newcols, int newsavelines) {
     savelines = newsavelines;
     fix_cpos;
 
-    deselect();
+    swap_screen(save_alt_which);
+
     update_sbar();
     term_update();
 }
@@ -286,63 +501,75 @@ void term_size(int newrows, int newcols, int newsavelines) {
 /*
  * Swap screens.
  */
-static void swap_screen (int which) {
+static void swap_screen(int which)
+{
     int t;
-    unsigned long tt;
+    tree234 *ttr;
 
     if (which == alt_which)
        return;
 
     alt_which = which;
 
-    for (t=0; t<rows*(cols+1); t++) {
-       tt = scrtop[t]; scrtop[t] = alttext[t]; alttext[t] = tt;
-    }
-
-    t = curs_x; curs_x = alt_x; alt_x = t;
-    t = curs_y; curs_y = alt_y; alt_y = t;
-    t = marg_t; marg_t = alt_t; alt_t = t;
-    t = marg_b; marg_b = alt_b; alt_b = t;
-    t = dec_om; dec_om = alt_om; alt_om = t;
-    t = wrap; wrap = alt_wrap; alt_wrap = t;
-    t = wrapnext; wrapnext = alt_wnext; alt_wnext = t;
-    t = insert; insert = alt_ins; alt_ins = t;
-    t = cset; cset = alt_cset; alt_cset = t;
+    ttr = alt_screen;
+    alt_screen = screen;
+    screen = ttr;
+    t = curs.x;
+    curs.x = alt_x;
+    alt_x = t;
+    t = curs.y;
+    curs.y = alt_y;
+    alt_y = t;
+    t = marg_t;
+    marg_t = alt_t;
+    alt_t = t;
+    t = marg_b;
+    marg_b = alt_b;
+    alt_b = t;
+    t = dec_om;
+    dec_om = alt_om;
+    alt_om = t;
+    t = wrap;
+    wrap = alt_wrap;
+    alt_wrap = t;
+    t = wrapnext;
+    wrapnext = alt_wnext;
+    alt_wnext = t;
+    t = insert;
+    insert = alt_ins;
+    alt_ins = t;
+    t = cset;
+    cset = alt_cset;
+    alt_cset = t;
+    t = utf;
+    utf = alt_utf;
+    alt_utf = t;
+    t = sco_acs;
+    sco_acs = alt_sco_acs;
+    alt_sco_acs = t;
 
     fix_cpos;
 }
 
 /*
- * Retrieve a character from `inbuf'.
- */
-static int inbuf_getc(void) {
-    if (inbuf_head == inbuf_reap)
-       return -1;                     /* EOF */
-    else {
-       int n = inbuf_reap;
-       inbuf_reap = (inbuf_reap+1) & INBUF_MASK;
-       return inbuf[n];
-    }
-}
-
-/*
  * Update the scroll bar.
  */
-static void update_sbar(void) {
-    int min;
+static void update_sbar(void)
+{
+    int nscroll;
+
+    nscroll = count234(scrollback);
 
-    min = (sbtop - text) / (cols+1);
-    set_sbar ((scrtop - text) / (cols+1) + rows - min,
-             (disptop - text) / (cols+1) - min,
-             rows);
+    set_sbar(nscroll + rows, nscroll + disptop, rows);
 }
 
 /*
  * Check whether the region bounded by the two pointers intersects
  * the scroll region, and de-select the on-screen selection if so.
  */
-static void check_selection (unsigned long *from, unsigned long *to) {
-    if (from < selend && selstart < to)
+static void check_selection(pos from, pos to)
+{
+    if (poslt(from, selend) && poslt(selstart, to))
        deselect();
 }
 
@@ -350,70 +577,90 @@ static void check_selection (unsigned long *from, unsigned long *to) {
  * Scroll the screen. (`lines' is +ve for scrolling forward, -ve
  * for backward.) `sb' is TRUE if the scrolling is permitted to
  * affect the scrollback buffer.
+ * 
+ * NB this function invalidates all pointers into lines of the
+ * screen data structures. In particular, you MUST call fix_cpos
+ * after calling scroll() and before doing anything else that
+ * uses the cpos shortcut pointer.
  */
-static void scroll (int topline, int botline, int lines, int sb) {
-    unsigned long *scroll_top;
-    int scroll_size, size, i;
-
-    scroll_top = scrtop + topline*(cols+1);
-    size = (lines < 0 ? -lines : lines) * (cols+1);
-    scroll_size = (botline - topline + 1) * (cols+1) - size;
-
-    if (lines > 0 && topline == 0 && alt_which == 0 && sb) {
-       /*
-        * Since we're going to scroll the top line and we're on the 
-        * scrolling screen let's also affect the scrollback buffer.
-        */
-       sbtop -= lines * (cols+1);
-       if (sbtop < text)
-           sbtop = text;
-       scroll_size += scroll_top - sbtop;
-       scroll_top = sbtop;
-       update_sbar();
-    }
+static void scroll(int topline, int botline, int lines, int sb)
+{
+    unsigned long *line, *line2;
+    int i;
 
-    if (scroll_size < 0) {
-       size += scroll_size;
-       scroll_size = 0;
-    }
+    if (topline != 0 || alt_which != 0)
+       sb = FALSE;
+
+    if (lines < 0) {
+       while (lines < 0) {
+           line = delpos234(screen, botline);
+            line = resizeline(line, cols);
+           for (i = 0; i < cols; i++)
+               line[i + 1] = erase_char;
+           line[cols + 1] = 0;
+           addpos234(screen, line, topline);
+
+           if (selstart.y >= topline && selstart.y <= botline) {
+               selstart.y++;
+               if (selstart.y > botline) {
+                   selstart.y = botline;
+                   selstart.x = 0;
+               }
+           }
+           if (selend.y >= topline && selend.y <= botline) {
+               selend.y++;
+               if (selend.y > botline) {
+                   selend.y = botline;
+                   selend.x = 0;
+               }
+           }
 
-    if (lines > 0) {
-       if (scroll_size)
-           memmove (scroll_top, scroll_top + size, scroll_size*TSIZE);
-       for (i = 0; i < size; i++)
-           scroll_top[i+scroll_size] = ERASE_CHAR;
-       if (selstart > scroll_top &&
-           selstart < scroll_top + size + scroll_size) {
-           selstart -= size;
-           if (selstart < scroll_top)
-               selstart = scroll_top;
-       }
-       if (selend > scroll_top &&
-           selend < scroll_top + size + scroll_size) {
-           selend -= size;
-           if (selend < scroll_top)
-               selend = scroll_top;
+           lines++;
        }
     } else {
-       if (scroll_size)
-           memmove (scroll_top + size, scroll_top, scroll_size*TSIZE);
-       for (i = 0; i < size; i++)
-           scroll_top[i] = ERASE_CHAR;
-       if (selstart > scroll_top &&
-           selstart < scroll_top + size + scroll_size) {
-           selstart += size;
-           if (selstart > scroll_top + size + scroll_size)
-               selstart = scroll_top + size + scroll_size;
-       }
-       if (selend > scroll_top &&
-           selend < scroll_top + size + scroll_size) {
-           selend += size;
-           if (selend > scroll_top + size + scroll_size)
-               selend = scroll_top + size + scroll_size;
+       while (lines > 0) {
+           line = delpos234(screen, topline);
+           if (sb && savelines > 0) {
+               int sblen = count234(scrollback);
+               /*
+                * We must add this line to the scrollback. We'll
+                * remove a line from the top of the scrollback to
+                * replace it, or allocate a new one if the
+                * scrollback isn't full.
+                */
+               if (sblen == savelines) {
+                   sblen--, line2 = delpos234(scrollback, 0);
+               } else {
+                   line2 = smalloc(TSIZE * (cols + 2));
+                   line2[0] = cols;
+               }
+               addpos234(scrollback, line, sblen);
+               line = line2;
+           }
+            line = resizeline(line, cols);
+           for (i = 0; i < cols; i++)
+               line[i + 1] = erase_char;
+           line[cols + 1] = 0;
+           addpos234(screen, line, botline);
+
+           if (selstart.y >= topline && selstart.y <= botline) {
+               selstart.y--;
+               if (selstart.y < topline) {
+                   selstart.y = topline;
+                   selstart.x = 0;
+               }
+           }
+           if (selend.y >= topline && selend.y <= botline) {
+               selend.y--;
+               if (selend.y < topline) {
+                   selend.y = topline;
+                   selend.x = 0;
+               }
+           }
+
+           lines--;
        }
     }
-
-    scroll_heuristic += lines;
 }
 
 /*
@@ -422,23 +669,24 @@ static void scroll (int topline, int botline, int lines, int sb) {
  * not to, 1 to disallow _passing_ the margins, and 2 to disallow
  * even _being_ outside the margins.
  */
-static void move (int x, int y, int marg_clip) {
+static void move(int x, int y, int marg_clip)
+{
     if (x < 0)
        x = 0;
     if (x >= cols)
-       x = cols-1;
+       x = cols - 1;
     if (marg_clip) {
-       if ((curs_y >= marg_t || marg_clip == 2) && y < marg_t)
+       if ((curs.y >= marg_t || marg_clip == 2) && y < marg_t)
            y = marg_t;
-       if ((curs_y <= marg_b || marg_clip == 2) && y > marg_b)
+       if ((curs.y <= marg_b || marg_clip == 2) && y > marg_b)
            y = marg_b;
     }
     if (y < 0)
        y = 0;
     if (y >= rows)
-       y = rows-1;
-    curs_x = x;
-    curs_y = y;
+       y = rows - 1;
+    curs.x = x;
+    curs.y = y;
     fix_cpos;
     wrapnext = FALSE;
 }
@@ -446,20 +694,32 @@ static void move (int x, int y, int marg_clip) {
 /*
  * Save or restore the cursor and SGR mode.
  */
-static void save_cursor(int save) {
+static void save_cursor(int save)
+{
     if (save) {
-       save_x = curs_x;
-       save_y = curs_y;
+       savecurs = curs;
        save_attr = curr_attr;
        save_cset = cset;
+       save_utf = utf;
        save_csattr = cset_attr[cset];
+       save_sco_acs = sco_acs;
     } else {
-       curs_x = save_x;
-       curs_y = save_y;
+       curs = savecurs;
+       /* Make sure the window hasn't shrunk since the save */
+       if (curs.x >= cols)
+           curs.x = cols - 1;
+       if (curs.y >= rows)
+           curs.y = rows - 1;
+
        curr_attr = save_attr;
        cset = save_cset;
+       utf = save_utf;
        cset_attr[cset] = save_csattr;
+       sco_acs = save_sco_acs;
        fix_cpos;
+       if (use_bce)
+           erase_char = (' ' | ATTR_ASCII |
+                        (curr_attr & (ATTR_FGMASK | ATTR_BGMASK)));
     }
 }
 
@@ -467,46 +727,76 @@ static void save_cursor(int save) {
  * Erase a large portion of the screen: the whole screen, or the
  * whole line, or parts thereof.
  */
-static void erase_lots (int line_only, int from_begin, int to_end) {
-    unsigned long *startpos, *endpos;
+static void erase_lots(int line_only, int from_begin, int to_end)
+{
+    pos start, end;
+    int erase_lattr;
+    unsigned long *ldata;
 
     if (line_only) {
-       startpos = cpos - curs_x;
-       endpos = startpos + cols+1;
+       start.y = curs.y;
+       start.x = 0;
+       end.y = curs.y + 1;
+       end.x = 0;
+       erase_lattr = FALSE;
     } else {
-       startpos = scrtop;
-       endpos = startpos + rows * (cols+1);
+       start.y = 0;
+       start.x = 0;
+       end.y = rows;
+       end.x = 0;
+       erase_lattr = TRUE;
+    }
+    if (!from_begin) {
+       start = curs;
+    }
+    if (!to_end) {
+       end = curs;
+       incpos(end);
+    }
+    check_selection(start, end);
+
+    /* Clear screen also forces a full window redraw, just in case. */
+    if (start.y == 0 && start.x == 0 && end.y == rows)
+       term_invalidate();
+
+    ldata = lineptr(start.y);
+    while (poslt(start, end)) {
+       if (start.x == cols && !erase_lattr)
+           ldata[start.x] &= ~LATTR_WRAPPED;
+       else
+           ldata[start.x] = erase_char;
+       if (incpos(start) && start.y < rows)
+           ldata = lineptr(start.y);
     }
-    if (!from_begin)
-       startpos = cpos;
-    if (!to_end)
-       endpos = cpos;
-    check_selection (startpos, endpos);
-    while (startpos < endpos)
-       *startpos++ = ERASE_CHAR;
 }
 
 /*
  * Insert or delete characters within the current line. n is +ve if
  * insertion is desired, and -ve for deletion.
  */
-static void insch (int n) {
+static void insch(int n)
+{
     int dir = (n < 0 ? -1 : +1);
     int m;
+    pos cursplus;
+    unsigned long *ldata;
 
     n = (n < 0 ? -n : n);
-    if (n > cols - curs_x)
-       n = cols - curs_x;
-    m = cols - curs_x - n;
-    check_selection (cpos, cpos+n);
+    if (n > cols - curs.x)
+       n = cols - curs.x;
+    m = cols - curs.x - n;
+    cursplus.y = curs.y;
+    cursplus.x = curs.x + n;
+    check_selection(curs, cursplus);
+    ldata = lineptr(curs.y);
     if (dir < 0) {
-       memmove (cpos, cpos+n, m*TSIZE);
+       memmove(ldata + curs.x, ldata + curs.x + n, m * TSIZE);
        while (n--)
-           cpos[m++] = ERASE_CHAR;
+           ldata[curs.x + m++] = erase_char;
     } else {
-       memmove (cpos+n, cpos, m*TSIZE);
+       memmove(ldata + curs.x + n, ldata + curs.x, m * TSIZE);
        while (n--)
-           cpos[n] = ERASE_CHAR;
+           ldata[curs.x + n] = erase_char;
     }
 }
 
@@ -514,56 +804,122 @@ static void insch (int n) {
  * Toggle terminal mode `mode' to state `state'. (`query' indicates
  * whether the mode is a DEC private one or a normal one.)
  */
-static void toggle_mode (int mode, int query, int state) {
-    if (query) switch (mode) {
-      case 1:                         /* application cursor keys */
-       app_cursor_keys = state;
-       break;
-      case 3:                         /* 80/132 columns */
-       deselect();
-       request_resize (state ? 132 : 80, rows);
-       break;
-      case 5:                         /* reverse video */
-       rvideo = state;
-       seen_disp_event = TRUE;
-       break;
-      case 6:                         /* DEC origin mode */
-       dec_om = state;
-       break;
-      case 7:                         /* auto wrap */
-       wrap = state;
-       break;
-      case 47:                        /* alternate screen */
-       deselect();
-       swap_screen (state);
-       disptop = scrtop;
-       break;
-    } else switch (mode) {
-      case 4:                         /* set insert mode */
-       insert = state;
-       break;
-    }
+static void toggle_mode(int mode, int query, int state)
+{
+    long ticks;
+
+    if (query)
+       switch (mode) {
+         case 1:                      /* application cursor keys */
+           app_cursor_keys = state;
+           break;
+         case 2:                      /* VT52 mode */
+           vt52_mode = !state;
+           if (vt52_mode) {
+               blink_is_real = FALSE;
+               vt52_bold = FALSE;
+           } else {
+               blink_is_real = cfg.blinktext;
+           }
+           break;
+         case 3:                      /* 80/132 columns */
+           deselect();
+           request_resize(state ? 132 : 80, rows, 1);
+           reset_132 = state;
+           break;
+         case 5:                      /* reverse video */
+           /*
+            * Toggle reverse video. If we receive an OFF within the
+            * visual bell timeout period after an ON, we trigger an
+            * effective visual bell, so that ESC[?5hESC[?5l will
+            * always be an actually _visible_ visual bell.
+            */
+           ticks = GetTickCount();
+           if (rvideo && !state &&    /* we're turning it off */
+               ticks < rvbell_timeout) {       /* and it's not long since it was turned on */
+               in_vbell = TRUE;       /* we may clear rvideo but we set in_vbell */
+               if (vbell_timeout < rvbell_timeout)     /* don't move vbell end forward */
+                   vbell_timeout = rvbell_timeout;     /* vbell end is at least then */
+           } else if (!rvideo && state) {
+               /* This is an ON, so we notice the time and save it. */
+               rvbell_timeout = ticks + VBELL_TIMEOUT;
+           }
+           rvideo = state;
+           seen_disp_event = TRUE;
+           if (state)
+               term_update();
+           break;
+         case 6:                      /* DEC origin mode */
+           dec_om = state;
+           break;
+         case 7:                      /* auto wrap */
+           wrap = state;
+           break;
+         case 8:                      /* auto key repeat */
+           repeat_off = !state;
+           break;
+         case 10:                     /* set local edit mode */
+           term_editing = state;
+           ldisc_send(NULL, 0);       /* cause ldisc to notice changes */
+           break;
+         case 25:                     /* enable/disable cursor */
+           compatibility2(OTHER, VT220);
+           cursor_on = state;
+           seen_disp_event = TRUE;
+           break;
+         case 47:                     /* alternate screen */
+           compatibility(OTHER);
+           deselect();
+           swap_screen(state);
+           disptop = 0;
+           break;
+         case 1000:                   /* xterm mouse 1 */
+           xterm_mouse = state ? 1 : 0;
+           set_raw_mouse_mode(state);
+           break;
+         case 1002:                   /* xterm mouse 2 */
+           xterm_mouse = state ? 2 : 0;
+           set_raw_mouse_mode(state);
+           break;
+    } else
+       switch (mode) {
+         case 4:                      /* set insert mode */
+           compatibility(VT102);
+           insert = state;
+           break;
+         case 12:                     /* set echo mode */
+           term_echoing = !state;
+           ldisc_send(NULL, 0);       /* cause ldisc to notice changes */
+           break;
+         case 20:                     /* Return sends ... */
+           cr_lf_return = state;
+           break;
+         case 34:                     /* Make cursor BIG */
+           compatibility2(OTHER, VT220);
+           big_cursor = !state;
+       }
 }
 
 /*
  * Process an OSC sequence: set window title or icon name.
  */
-static void do_osc(void) {
+static void do_osc(void)
+{
     if (osc_w) {
        while (osc_strlen--)
-           wordness[(unsigned char)osc_string[osc_strlen]] = esc_args[0];
+           wordness[(unsigned char) osc_string[osc_strlen]] = esc_args[0];
     } else {
        osc_string[osc_strlen] = '\0';
        switch (esc_args[0]) {
          case 0:
          case 1:
-           set_icon (osc_string);
+           set_icon(osc_string);
            if (esc_args[0] == 1)
                break;
            /* fall through: parameter 0 means set both */
          case 2:
          case 21:
-           set_title (osc_string);
+           set_title(osc_string);
            break;
        }
     }
@@ -574,664 +930,1784 @@ static void do_osc(void) {
  * in-memory display. There's a big state machine in here to
  * process escape sequences...
  */
-void term_out(void) {
-    int c;
+void term_out(void)
+{
+    int c, inbuf_reap;
 
-    while ( (c = inbuf_getc()) != -1) {
-#ifdef LOG
-       {
-           static FILE *fp = NULL;
-           if (!fp) fp = fopen("putty.log", "wb");
-           if (fp) fputc (c, fp);
+    for (inbuf_reap = 0; inbuf_reap < inbuf_head; inbuf_reap++) {
+       c = inbuf[inbuf_reap];
+
+       /*
+        * Optionally log the session traffic to a file. Useful for
+        * debugging and possibly also useful for actual logging.
+        */
+       logtraffic((unsigned char) c, LGTYP_DEBUG);
+
+       /* Note only VT220+ are 8-bit VT102 is seven bit, it shouldn't even
+        * be able to display 8-bit characters, but I'll let that go 'cause
+        * of i18n.
+        */
+
+       /* First see about all those translations. */
+       if (termstate == TOPLEVEL) {
+           if (in_utf)
+               switch (utf_state) {
+                 case 0:
+                   if (c < 0x80) {
+                       /* UTF-8 must be stateless so we ignore iso2022. */
+                       if (unitab_ctrl[c] != 0xFF) 
+                            c = unitab_ctrl[c];
+                       else c = ((unsigned char)c) | ATTR_ASCII;
+                       break;
+                   } else if ((c & 0xe0) == 0xc0) {
+                       utf_size = utf_state = 1;
+                       utf_char = (c & 0x1f);
+                   } else if ((c & 0xf0) == 0xe0) {
+                       utf_size = utf_state = 2;
+                       utf_char = (c & 0x0f);
+                   } else if ((c & 0xf8) == 0xf0) {
+                       utf_size = utf_state = 3;
+                       utf_char = (c & 0x07);
+                   } else if ((c & 0xfc) == 0xf8) {
+                       utf_size = utf_state = 4;
+                       utf_char = (c & 0x03);
+                   } else if ((c & 0xfe) == 0xfc) {
+                       utf_size = utf_state = 5;
+                       utf_char = (c & 0x01);
+                   } else {
+                       c = UCSERR;
+                       break;
+                   }
+                   continue;
+                 case 1:
+                 case 2:
+                 case 3:
+                 case 4:
+                 case 5:
+                   if ((c & 0xC0) != 0x80) {
+                       inbuf_reap--;  /* This causes the faulting character */
+                       c = UCSERR;    /* to be logged twice - not really a */
+                       utf_state = 0; /* serious problem. */
+                       break;
+                   }
+                   utf_char = (utf_char << 6) | (c & 0x3f);
+                   if (--utf_state)
+                       continue;
+
+                   c = utf_char;
+
+                   /* Is somebody trying to be evil! */
+                   if (c < 0x80 ||
+                       (c < 0x800 && utf_size >= 2) ||
+                       (c < 0x10000 && utf_size >= 3) ||
+                       (c < 0x200000 && utf_size >= 4) ||
+                       (c < 0x4000000 && utf_size >= 5))
+                       c = UCSERR;
+
+                   /* Unicode line separator and paragraph separator are CR-LF */
+                   if (c == 0x2028 || c == 0x2029)
+                       c = 0x85;
+
+                   /* High controls are probably a Baaad idea too. */
+                   if (c < 0xA0)
+                       c = 0xFFFD;
+
+                   /* The UTF-16 surrogates are not nice either. */
+                   /*       The standard give the option of decoding these: 
+                    *       I don't want to! */
+                   if (c >= 0xD800 && c < 0xE000)
+                       c = UCSERR;
+
+                   /* ISO 10646 characters now limited to UTF-16 range. */
+                   if (c > 0x10FFFF)
+                       c = UCSERR;
+
+                   /* This is currently a TagPhobic application.. */
+                   if (c >= 0xE0000 && c <= 0xE007F)
+                       continue;
+
+                   /* U+FEFF is best seen as a null. */
+                   if (c == 0xFEFF)
+                       continue;
+                   /* But U+FFFE is an error. */
+                   if (c == 0xFFFE || c == 0xFFFF)
+                       c = UCSERR;
+
+                   /* Oops this is a 16bit implementation */
+                   if (c >= 0x10000)
+                       c = 0xFFFD;
+                   break;
+           }
+           /* Are we in the nasty ACS mode? Note: no sco in utf mode. */
+           else if(sco_acs && 
+                   (c!='\033' && c!='\n' && c!='\r' && c!='\b'))
+           {
+              if (sco_acs == 2) c ^= 0x80;
+              c |= ATTR_SCOACS;
+           } else {
+               switch (cset_attr[cset]) {
+                   /* 
+                    * Linedraw characters are different from 'ESC ( B'
+                    * only for a small range. For ones outside that
+                    * range, make sure we use the same font as well as
+                    * the same encoding.
+                    */
+                 case ATTR_LINEDRW:
+                   if (unitab_ctrl[c] != 0xFF)
+                       c = unitab_ctrl[c];
+                   else
+                       c = ((unsigned char) c) | ATTR_LINEDRW;
+                   break;
+
+                 case ATTR_GBCHR:
+                   /* If UK-ASCII, make the '#' a LineDraw Pound */
+                   if (c == '#') {
+                       c = '}' | ATTR_LINEDRW;
+                       break;
+                   }
+                 /*FALLTHROUGH*/ case ATTR_ASCII:
+                   if (unitab_ctrl[c] != 0xFF)
+                       c = unitab_ctrl[c];
+                   else
+                       c = ((unsigned char) c) | ATTR_ASCII;
+                   break;
+               case ATTR_SCOACS:
+                   if (c>=' ') c = ((unsigned char)c) | ATTR_SCOACS;
+                   break;
+               }
+           }
        }
-#endif
-       if( termstate < DO_CTRLS && (c&0x60) == 0 ) {
+
+       /* How about C1 controls ? */
+       if ((c & -32) == 0x80 && termstate < DO_CTRLS && !vt52_mode &&
+           has_compat(VT220)) {
+           termstate = SEEN_ESC;
+           esc_query = FALSE;
+           c = '@' + (c & 0x1F);
+       }
+
+       /* Or the GL control. */
+       if (c == '\177' && termstate < DO_CTRLS && has_compat(OTHER)) {
+           if (curs.x && !wrapnext)
+               curs.x--;
+           wrapnext = FALSE;
+           fix_cpos;
+           *cpos = (' ' | curr_attr | ATTR_ASCII);
+       } else
+           /* Or normal C0 controls. */
+       if ((c & -32) == 0 && termstate < DO_CTRLS) {
            switch (c) {
              case '\005':             /* terminal type query */
-               ldisc->send ("PuTTY\r", 6);
+               /* Strictly speaking this is VT100 but a VT100 defaults to
+                * no response. Other terminals respond at their option.
+                *
+                * Don't put a CR in the default string as this tends to
+                * upset some weird software.
+                *
+                * An xterm returns "xterm" (5 characters)
+                */
+               compatibility(ANSIMIN);
+               {
+                   char abuf[256], *s, *d;
+                   int state = 0;
+                   for (s = cfg.answerback, d = abuf; *s; s++) {
+                       if (state) {
+                           if (*s >= 'a' && *s <= 'z')
+                               *d++ = (*s - ('a' - 1));
+                           else if ((*s >= '@' && *s <= '_') ||
+                                    *s == '?' || (*s & 0x80))
+                               *d++ = ('@' ^ *s);
+                           else if (*s == '~')
+                               *d++ = '^';
+                           state = 0;
+                       } else if (*s == '^') {
+                           state = 1;
+                       } else
+                           *d++ = *s;
+                   }
+                   lpage_send(CP_ACP, abuf, d - abuf);
+               }
                break;
              case '\007':
-               beep();
-               disptop = scrtop;
+               {
+                   struct beeptime *newbeep;
+                   long ticks;
+
+                   ticks = GetTickCount();
+
+                   if (!beep_overloaded) {
+                       newbeep = smalloc(sizeof(struct beeptime));
+                       newbeep->ticks = ticks;
+                       newbeep->next = NULL;
+                       if (!beephead)
+                           beephead = newbeep;
+                       else
+                           beeptail->next = newbeep;
+                       beeptail = newbeep;
+                       nbeeps++;
+                   }
+
+                   /*
+                    * Throw out any beeps that happened more than
+                    * t seconds ago.
+                    */
+                   while (beephead &&
+                          beephead->ticks < ticks - cfg.bellovl_t) {
+                       struct beeptime *tmp = beephead;
+                       beephead = tmp->next;
+                       sfree(tmp);
+                       if (!beephead)
+                           beeptail = NULL;
+                       nbeeps--;
+                   }
+
+                   if (cfg.bellovl && beep_overloaded &&
+                       ticks - lastbeep >= cfg.bellovl_s) {
+                       /*
+                        * If we're currently overloaded and the
+                        * last beep was more than s seconds ago,
+                        * leave overload mode.
+                        */
+                       beep_overloaded = FALSE;
+                   } else if (cfg.bellovl && !beep_overloaded &&
+                              nbeeps >= cfg.bellovl_n) {
+                       /*
+                        * Now, if we have n or more beeps
+                        * remaining in the queue, go into overload
+                        * mode.
+                        */
+                       beep_overloaded = TRUE;
+                   }
+                   lastbeep = ticks;
+
+                   /*
+                    * Perform an actual beep if we're not overloaded.
+                    */
+                   if (!cfg.bellovl || !beep_overloaded) {
+                       beep(cfg.beep);
+                       if (cfg.beep == BELL_VISUAL) {
+                           in_vbell = TRUE;
+                           vbell_timeout = ticks + VBELL_TIMEOUT;
+                           term_update();
+                       }
+                   }
+                   disptop = 0;
+               }
                break;
              case '\b':
-               if (curs_x == 0 && curs_y > 0)
-                   curs_x = cols-1, curs_y--;
+               if (curs.x == 0 && (curs.y == 0 || wrap == 0));
+               else if (curs.x == 0 && curs.y > 0)
+                   curs.x = cols - 1, curs.y--;
                else if (wrapnext)
                    wrapnext = FALSE;
                else
-                   curs_x--;
+                   curs.x--;
                fix_cpos;
                seen_disp_event = TRUE;
                break;
              case '\016':
+               compatibility(VT100);
                cset = 1;
                break;
              case '\017':
+               compatibility(VT100);
                cset = 0;
                break;
              case '\033':
-               termstate = SEEN_ESC;
-               break;
-             case 0233:
-               termstate = SEEN_CSI;
-               esc_nargs = 1;
-               esc_args[0] = ARG_DEFAULT;
-               esc_query = FALSE;
-               break;
-             case 0235:
-               termstate = SEEN_OSC;
-               esc_args[0] = 0;
+               if (vt52_mode)
+                   termstate = VT52_ESC;
+               else {
+                   compatibility(ANSIMIN);
+                   termstate = SEEN_ESC;
+                   esc_query = FALSE;
+               }
                break;
              case '\r':
-               curs_x = 0;
+               curs.x = 0;
                wrapnext = FALSE;
                fix_cpos;
                seen_disp_event = TRUE;
+               paste_hold = 0;
+               logtraffic((unsigned char) c, LGTYP_ASCII);
                break;
-             case '\013':
              case '\014':
+               if (has_compat(SCOANSI)) {
+                   move(0, 0, 0);
+                   erase_lots(FALSE, FALSE, TRUE);
+                   disptop = 0;
+                   wrapnext = FALSE;
+                   seen_disp_event = 1;
+                   break;
+               }
+             case '\013':
+               compatibility(VT100);
              case '\n':
-               if (curs_y == marg_b)
-                   scroll (marg_t, marg_b, 1, TRUE);
-               else if (curs_y < rows-1)
-                   curs_y++;
+               if (curs.y == marg_b)
+                   scroll(marg_t, marg_b, 1, TRUE);
+               else if (curs.y < rows - 1)
+                   curs.y++;
                if (cfg.lfhascr)
-                   curs_x = 0;
+                   curs.x = 0;
                fix_cpos;
                wrapnext = FALSE;
                seen_disp_event = 1;
-               nl_count++;
+               paste_hold = 0;
+               logtraffic((unsigned char) c, LGTYP_ASCII);
                break;
              case '\t':
-               do {
-                   curs_x++;
-               } while (curs_x < cols-1 && !tabs[curs_x]);
-               if (curs_x >= cols)
-                   curs_x = cols-1;
                {
-                   unsigned long *old_cpos = cpos;
+                   pos old_curs = curs;
+                   unsigned long *ldata = lineptr(curs.y);
+
+                   do {
+                       curs.x++;
+                   } while (curs.x < cols - 1 && !tabs[curs.x]);
+
+                   if ((ldata[cols] & LATTR_MODE) != LATTR_NORM) {
+                       if (curs.x >= cols / 2)
+                           curs.x = cols / 2 - 1;
+                   } else {
+                       if (curs.x >= cols)
+                           curs.x = cols - 1;
+                   }
+
                    fix_cpos;
-                   check_selection (old_cpos, cpos);
+                   check_selection(old_curs, curs);
                }
                seen_disp_event = TRUE;
                break;
            }
-       }
-       else switch (termstate) {
-         case TOPLEVEL:
-           if (c >= ' ' && c != 0234) {
-               if (wrapnext) {
-                   cpos[1] ATTR_WRAPPED;
-                   if (curs_y == marg_b)
-                       scroll (marg_t, marg_b, 1, TRUE);
-                   else if (curs_y < rows-1)
-                       curs_y++;
-                   curs_x = 0;
+       } else
+           switch (termstate) {
+             case TOPLEVEL:
+               /* Only graphic characters get this far, ctrls are stripped above */
+               if (wrapnext && wrap) {
+                   cpos[1] |= LATTR_WRAPPED;
+                   if (curs.y == marg_b)
+                       scroll(marg_t, marg_b, 1, TRUE);
+                   else if (curs.y < rows - 1)
+                       curs.y++;
+                   curs.x = 0;
                    fix_cpos;
                    wrapnext = FALSE;
-                   nl_count++;
                }
                if (insert)
-                   insch (1);
-               check_selection (cpos, cpos+1);
-               *cpos++ = xlat_tty2scr((unsigned char)c) | curr_attr |
-                   (c <= 0x7F ? cset_attr[cset] : ATTR_ASCII);
-               curs_x++;
-               if (curs_x == cols) {
+                   insch(1);
+               if (selstate != NO_SELECTION) {
+                   pos cursplus = curs;
+                   incpos(cursplus);
+                   check_selection(curs, cursplus);
+               }
+               if ((c & CSET_MASK) == ATTR_ASCII || (c & CSET_MASK) == 0)
+                   logtraffic((unsigned char) c, LGTYP_ASCII);
+               {
+                   extern int wcwidth(wchar_t ucs);
+                   int width = 0;
+                   if (DIRECT_CHAR(c))
+                       width = 1;
+                   if (!width)
+                       width = wcwidth((wchar_t) c);
+                   switch (width) {
+                     case 2:
+                       if (curs.x + 1 != cols) {
+                           *cpos++ = c | ATTR_WIDE | curr_attr;
+                           *cpos++ = UCSWIDE | curr_attr;
+                           curs.x++;
+                           break;
+                       }
+                     case 1:
+                       *cpos++ = c | curr_attr;
+                       break;
+                     default:
+                       continue;
+                   }
+               }
+               curs.x++;
+               if (curs.x == cols) {
                    cpos--;
-                   curs_x--;
-                   wrapnext = wrap;
+                   curs.x--;
+                   wrapnext = TRUE;
+                   if (wrap && vt52_mode) {
+                       cpos[1] |= LATTR_WRAPPED;
+                       if (curs.y == marg_b)
+                           scroll(marg_t, marg_b, 1, TRUE);
+                       else if (curs.y < rows - 1)
+                           curs.y++;
+                       curs.x = 0;
+                       fix_cpos;
+                       wrapnext = FALSE;
+                   }
                }
                seen_disp_event = 1;
-           }
-           break;
-
-         case IGNORE_NEXT:
-           termstate = TOPLEVEL;
-           break;
-         case OSC_MAYBE_ST:
-           /*
-            * This state is virtually identical to SEEN_ESC, with the
-            * exception that we have an OSC sequence in the pipeline,
-            * and _if_ we see a backslash, we process it.
-            */
-           if (c == '\\') {
-               do_osc();
-               termstate = TOPLEVEL;
-               break;
-           }
-           /* else fall through */
-         case SEEN_ESC:
-           termstate = TOPLEVEL;
-           switch (c) {
-             case ' ':                /* some weird sequence? */
-               termstate = IGNORE_NEXT;
-               break;
-             case '[':                /* enter CSI mode */
-               termstate = SEEN_CSI;
-               esc_nargs = 1;
-               esc_args[0] = ARG_DEFAULT;
-               esc_query = FALSE;
-               break;
-             case ']':                /* xterm escape sequences */
-               termstate = SEEN_OSC;
-               esc_args[0] = 0;
-               break;
-             case '(':                /* should set GL */
-               termstate = SET_GL;
-               break;
-             case ')':                /* should set GR */
-               termstate = SET_GR;
-               break;
-             case '7':                /* save cursor */
-               save_cursor (TRUE);
                break;
-             case '8':                /* restore cursor */
-               save_cursor (FALSE);
-               seen_disp_event = TRUE;
-               break;
-             case '=':
-               app_keypad_keys = TRUE;
-               break;
-             case '>':
-               app_keypad_keys = FALSE;
-               break;
-             case 'D':                /* exactly equivalent to LF */
-               if (curs_y == marg_b)
-                   scroll (marg_t, marg_b, 1, TRUE);
-               else if (curs_y < rows-1)
-                   curs_y++;
-               fix_cpos;
-               wrapnext = FALSE;
-               seen_disp_event = TRUE;
-               nl_count++;
-               break;
-             case 'E':                /* exactly equivalent to CR-LF */
-               curs_x = 0;
-               wrapnext = FALSE;
-               if (curs_y == marg_b)
-                   scroll (marg_t, marg_b, 1, TRUE);
-               else if (curs_y < rows-1)
-                   curs_y++;
-               fix_cpos;
-               wrapnext = FALSE;
-               nl_count++;
-               seen_disp_event = TRUE;
-               break;
-             case 'M':                /* reverse index - backwards LF */
-               if (curs_y == marg_t)
-                   scroll (marg_t, marg_b, -1, TRUE);
-               else if (curs_y > 0)
-                   curs_y--;
-               fix_cpos;
-               wrapnext = FALSE;
-               seen_disp_event = TRUE;
-               break;
-             case 'Z':                /* terminal type query */
-               ldisc->send ("\033[?6c", 5);
-               break;
-             case 'c':                /* restore power-on settings */
-               power_on();
-               fix_cpos;
-               disptop = scrtop;
-               seen_disp_event = TRUE;
-               break;
-             case '#':                /* ESC # 8 fills screen with Es :-) */
-               termstate = SEEN_ESCHASH;
-               break;
-             case 'H':                /* set a tab */
-               tabs[curs_x] = TRUE;
-               break;
-           }
-           break;
-         case SEEN_CSI:
-           termstate = TOPLEVEL;      /* default */
-           switch (c) {
-             case '0': case '1': case '2': case '3': case '4':
-             case '5': case '6': case '7': case '8': case '9':
-               if (esc_nargs <= ARGS_MAX) {
-                   if (esc_args[esc_nargs-1] == ARG_DEFAULT)
-                       esc_args[esc_nargs-1] = 0;
-                   esc_args[esc_nargs-1] =
-                       10 * esc_args[esc_nargs-1] + c - '0';
-               }
-               termstate = SEEN_CSI;
-               break;
-             case ';':
-               if (++esc_nargs <= ARGS_MAX)
-                   esc_args[esc_nargs-1] = ARG_DEFAULT;
-               termstate = SEEN_CSI;
-               break;
-             case '?':
-               esc_query = TRUE;
-               termstate = SEEN_CSI;
-               break;
-             case 'A':                /* move up N lines */
-               move (curs_x, curs_y - def(esc_args[0], 1), 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'B': case 'e':      /* move down N lines */
-               move (curs_x, curs_y + def(esc_args[0], 1), 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'C': case 'a':      /* move right N cols */
-               move (curs_x + def(esc_args[0], 1), curs_y, 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'D':                /* move left N cols */
-               move (curs_x - def(esc_args[0], 1), curs_y, 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'E':                /* move down N lines and CR */
-               move (0, curs_y + def(esc_args[0], 1), 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'F':                /* move up N lines and CR */
-               move (0, curs_y - def(esc_args[0], 1), 1);
-               seen_disp_event = TRUE;
-               break;
-             case 'G': case '`':      /* set horizontal posn */
-               move (def(esc_args[0], 1) - 1, curs_y, 0);
-               seen_disp_event = TRUE;
-               break;
-             case 'd':                /* set vertical posn */
-               move (curs_x, (dec_om ? marg_t : 0) + def(esc_args[0], 1) - 1,
-                     (dec_om ? 2 : 0));
-               seen_disp_event = TRUE;
-               break;
-             case 'H': case 'f':      /* set horz and vert posns at once */
-               if (esc_nargs < 2)
-                   esc_args[1] = ARG_DEFAULT;
-               move (def(esc_args[1], 1) - 1,
-                     (dec_om ? marg_t : 0) + def(esc_args[0], 1) - 1,
-                     (dec_om ? 2 : 0));
-               seen_disp_event = TRUE;
-               break;
-             case 'J':                /* erase screen or parts of it */
-               {
-                   unsigned int i = def(esc_args[0], 0) + 1;
-                   if (i > 3)
-                       i = 0;
-                   erase_lots(FALSE, !!(i & 2), !!(i & 1));
+
+             case OSC_MAYBE_ST:
+               /*
+                * This state is virtually identical to SEEN_ESC, with the
+                * exception that we have an OSC sequence in the pipeline,
+                * and _if_ we see a backslash, we process it.
+                */
+               if (c == '\\') {
+                   do_osc();
+                   termstate = TOPLEVEL;
+                   break;
                }
-               disptop = scrtop;
-               seen_disp_event = TRUE;
-               break;
-             case 'K':                /* erase line or parts of it */
-               {
-                   unsigned int i = def(esc_args[0], 0) + 1;
-                   if (i > 3)
-                       i = 0;
-                   erase_lots(TRUE, !!(i & 2), !!(i & 1));
+               /* else fall through */
+             case SEEN_ESC:
+               if (c >= ' ' && c <= '/') {
+                   if (esc_query)
+                       esc_query = -1;
+                   else
+                       esc_query = c;
+                   break;
                }
-               seen_disp_event = TRUE;
-               break;
-             case 'L':                /* insert lines */
-               if (curs_y <= marg_b)
-                   scroll (curs_y, marg_b, -def(esc_args[0], 1), FALSE);
-               seen_disp_event = TRUE;
-               break;
-             case 'M':                /* delete lines */
-               if (curs_y <= marg_b)
-                   scroll (curs_y, marg_b, def(esc_args[0], 1), TRUE);
-               seen_disp_event = TRUE;
-               break;
-             case '@':                /* insert chars */
-               insch (def(esc_args[0], 1));
-               seen_disp_event = TRUE;
-               break;
-             case 'P':                /* delete chars */
-               insch (-def(esc_args[0], 1));
-               seen_disp_event = TRUE;
-               break;
-             case 'c':                /* terminal type query */
-               ldisc->send ("\033[?6c", 5);
-               break;
-             case 'n':                /* cursor position query */
-               if (esc_args[0] == 6) {
-                   char buf[32];
-                   sprintf (buf, "\033[%d;%dR", curs_y + 1, curs_x + 1);
-                   ldisc->send (buf, strlen(buf));
-               }
-               break;
-             case 'h':                /* toggle a mode to high */
-               toggle_mode (esc_args[0], esc_query, TRUE);
-               break;
-             case 'l':                /* toggle a mode to low */
-               toggle_mode (esc_args[0], esc_query, FALSE);
-               break;
-             case 'g':                /* clear tabs */
-               if (esc_nargs == 1) {
-                   if (esc_args[0] == 0) {
-                       tabs[curs_x] = FALSE;
-                   } else if (esc_args[0] == 3) {
-                       int i;
-                       for (i = 0; i < cols; i++)
-                           tabs[i] = FALSE;
+               termstate = TOPLEVEL;
+               switch (ANSI(c, esc_query)) {
+                 case '[':            /* enter CSI mode */
+                   termstate = SEEN_CSI;
+                   esc_nargs = 1;
+                   esc_args[0] = ARG_DEFAULT;
+                   esc_query = FALSE;
+                   break;
+                 case ']':            /* xterm escape sequences */
+                   /* Compatibility is nasty here, xterm, linux, decterm yuk! */
+                   compatibility(OTHER);
+                   termstate = SEEN_OSC;
+                   esc_args[0] = 0;
+                   break;
+                 case '7':            /* save cursor */
+                   compatibility(VT100);
+                   save_cursor(TRUE);
+                   break;
+                 case '8':            /* restore cursor */
+                   compatibility(VT100);
+                   save_cursor(FALSE);
+                   seen_disp_event = TRUE;
+                   break;
+                 case '=':
+                   compatibility(VT100);
+                   app_keypad_keys = TRUE;
+                   break;
+                 case '>':
+                   compatibility(VT100);
+                   app_keypad_keys = FALSE;
+                   break;
+                 case 'D':            /* exactly equivalent to LF */
+                   compatibility(VT100);
+                   if (curs.y == marg_b)
+                       scroll(marg_t, marg_b, 1, TRUE);
+                   else if (curs.y < rows - 1)
+                       curs.y++;
+                   fix_cpos;
+                   wrapnext = FALSE;
+                   seen_disp_event = TRUE;
+                   break;
+                 case 'E':            /* exactly equivalent to CR-LF */
+                   compatibility(VT100);
+                   curs.x = 0;
+                   if (curs.y == marg_b)
+                       scroll(marg_t, marg_b, 1, TRUE);
+                   else if (curs.y < rows - 1)
+                       curs.y++;
+                   fix_cpos;
+                   wrapnext = FALSE;
+                   seen_disp_event = TRUE;
+                   break;
+                 case 'M':            /* reverse index - backwards LF */
+                   compatibility(VT100);
+                   if (curs.y == marg_t)
+                       scroll(marg_t, marg_b, -1, TRUE);
+                   else if (curs.y > 0)
+                       curs.y--;
+                   fix_cpos;
+                   wrapnext = FALSE;
+                   seen_disp_event = TRUE;
+                   break;
+                 case 'Z':            /* terminal type query */
+                   compatibility(VT100);
+                   ldisc_send(id_string, strlen(id_string));
+                   break;
+                 case 'c':            /* restore power-on settings */
+                   compatibility(VT100);
+                   power_on();
+                   if (reset_132) {
+                       request_resize(80, rows, 1);
+                       reset_132 = 0;
+                   }
+                   fix_cpos;
+                   disptop = 0;
+                   seen_disp_event = TRUE;
+                   break;
+                 case 'H':            /* set a tab */
+                   compatibility(VT100);
+                   tabs[curs.x] = TRUE;
+                   break;
+
+                 case ANSI('8', '#'):  /* ESC # 8 fills screen with Es :-) */
+                   compatibility(VT100);
+                   {
+                       unsigned long *ldata;
+                       int i, j;
+                       pos scrtop, scrbot;
+
+                       for (i = 0; i < rows; i++) {
+                           ldata = lineptr(i);
+                           for (j = 0; j < cols; j++)
+                               ldata[j] = ATTR_DEFAULT | 'E';
+                           ldata[cols] = 0;
+                       }
+                       disptop = 0;
+                       seen_disp_event = TRUE;
+                       scrtop.x = scrtop.y = 0;
+                       scrbot.x = 0;
+                       scrbot.y = rows;
+                       check_selection(scrtop, scrbot);
                    }
+                   break;
+
+                 case ANSI('3', '#'):
+                 case ANSI('4', '#'):
+                 case ANSI('5', '#'):
+                 case ANSI('6', '#'):
+                   compatibility(VT100);
+                   {
+                       unsigned long nlattr;
+                       unsigned long *ldata;
+                       switch (ANSI(c, esc_query)) {
+                         case ANSI('3', '#'):
+                           nlattr = LATTR_TOP;
+                           break;
+                         case ANSI('4', '#'):
+                           nlattr = LATTR_BOT;
+                           break;
+                         case ANSI('5', '#'):
+                           nlattr = LATTR_NORM;
+                           break;
+                         default: /* spiritually case ANSI('6', '#'): */
+                           nlattr = LATTR_WIDE;
+                           break;
+                       }
+                       ldata = lineptr(curs.y);
+                       ldata[cols] &= ~LATTR_MODE;
+                       ldata[cols] |= nlattr;
+                   }
+                   break;
+
+                 case ANSI('A', '('):
+                   compatibility(VT100);
+                   cset_attr[0] = ATTR_GBCHR;
+                   break;
+                 case ANSI('B', '('):
+                   compatibility(VT100);
+                   cset_attr[0] = ATTR_ASCII;
+                   break;
+                 case ANSI('0', '('):
+                   compatibility(VT100);
+                   cset_attr[0] = ATTR_LINEDRW;
+                   break;
+                 case ANSI('U', '('): 
+                   compatibility(OTHER);
+                   cset_attr[0] = ATTR_SCOACS; 
+                   break;
+
+                 case ANSI('A', ')'):
+                   compatibility(VT100);
+                   cset_attr[1] = ATTR_GBCHR;
+                   break;
+                 case ANSI('B', ')'):
+                   compatibility(VT100);
+                   cset_attr[1] = ATTR_ASCII;
+                   break;
+                 case ANSI('0', ')'):
+                   compatibility(VT100);
+                   cset_attr[1] = ATTR_LINEDRW;
+                   break;
+                 case ANSI('U', ')'): 
+                   compatibility(OTHER);
+                   cset_attr[1] = ATTR_SCOACS; 
+                   break;
+
+                 case ANSI('8', '%'):  /* Old Linux code */
+                 case ANSI('G', '%'):
+                   compatibility(OTHER);
+                   utf = 1;
+                   break;
+                 case ANSI('@', '%'):
+                   compatibility(OTHER);
+                   utf = 0;
+                   break;
                }
                break;
-             case 'r':                /* set scroll margins */
-               if (!esc_query && esc_nargs <= 2) {
-                   int top, bot;
-                   top = def(esc_args[0], 1) - 1;
-                   if (top < 0)
-                       top = 0;
-                   bot = (esc_nargs <= 1 || esc_args[1] == 0 ? rows :
-                          def(esc_args[1], rows)) - 1;
-                   if (bot >= rows)
-                       bot = rows-1;
-                   if (top <= bot) {
-                       marg_t = top;
-                       marg_b = bot;
-                       curs_x = 0;
+             case SEEN_CSI:
+               termstate = TOPLEVEL;  /* default */
+               if (isdigit(c)) {
+                   if (esc_nargs <= ARGS_MAX) {
+                       if (esc_args[esc_nargs - 1] == ARG_DEFAULT)
+                           esc_args[esc_nargs - 1] = 0;
+                       esc_args[esc_nargs - 1] =
+                           10 * esc_args[esc_nargs - 1] + c - '0';
+                   }
+                   termstate = SEEN_CSI;
+               } else if (c == ';') {
+                   if (++esc_nargs <= ARGS_MAX)
+                       esc_args[esc_nargs - 1] = ARG_DEFAULT;
+                   termstate = SEEN_CSI;
+               } else if (c < '@') {
+                   if (esc_query)
+                       esc_query = -1;
+                   else if (c == '?')
+                       esc_query = TRUE;
+                   else
+                       esc_query = c;
+                   termstate = SEEN_CSI;
+               } else
+                   switch (ANSI(c, esc_query)) {
+                     case 'A':       /* move up N lines */
+                       move(curs.x, curs.y - def(esc_args[0], 1), 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'e':       /* move down N lines */
+                       compatibility(ANSI);
+                       /* FALLTHROUGH */
+                     case 'B':
+                       move(curs.x, curs.y + def(esc_args[0], 1), 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case ANSI('c', '>'):      /* report xterm version */
+                       compatibility(OTHER);
+                       /* this reports xterm version 136 so that VIM can
+                          use the drag messages from the mouse reporting */
+                       ldisc_send("\033[>0;136;0c", 11);
+                       break;
+                     case 'a':       /* move right N cols */
+                       compatibility(ANSI);
+                       /* FALLTHROUGH */
+                     case 'C':
+                       move(curs.x + def(esc_args[0], 1), curs.y, 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'D':       /* move left N cols */
+                       move(curs.x - def(esc_args[0], 1), curs.y, 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'E':       /* move down N lines and CR */
+                       compatibility(ANSI);
+                       move(0, curs.y + def(esc_args[0], 1), 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'F':       /* move up N lines and CR */
+                       compatibility(ANSI);
+                       move(0, curs.y - def(esc_args[0], 1), 1);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'G':
+                     case '`':       /* set horizontal posn */
+                       compatibility(ANSI);
+                       move(def(esc_args[0], 1) - 1, curs.y, 0);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'd':       /* set vertical posn */
+                       compatibility(ANSI);
+                       move(curs.x,
+                            (dec_om ? marg_t : 0) + def(esc_args[0],
+                                                        1) - 1,
+                            (dec_om ? 2 : 0));
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'H':
+                     case 'f':       /* set horz and vert posns at once */
+                       if (esc_nargs < 2)
+                           esc_args[1] = ARG_DEFAULT;
+                       move(def(esc_args[1], 1) - 1,
+                            (dec_om ? marg_t : 0) + def(esc_args[0],
+                                                        1) - 1,
+                            (dec_om ? 2 : 0));
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'J':       /* erase screen or parts of it */
+                       {
+                           unsigned int i = def(esc_args[0], 0) + 1;
+                           if (i > 3)
+                               i = 0;
+                           erase_lots(FALSE, !!(i & 2), !!(i & 1));
+                       }
+                       disptop = 0;
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'K':       /* erase line or parts of it */
+                       {
+                           unsigned int i = def(esc_args[0], 0) + 1;
+                           if (i > 3)
+                               i = 0;
+                           erase_lots(TRUE, !!(i & 2), !!(i & 1));
+                       }
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'L':       /* insert lines */
+                       compatibility(VT102);
+                       if (curs.y <= marg_b)
+                           scroll(curs.y, marg_b, -def(esc_args[0], 1),
+                                  FALSE);
+                       fix_cpos;
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'M':       /* delete lines */
+                       compatibility(VT102);
+                       if (curs.y <= marg_b)
+                           scroll(curs.y, marg_b, def(esc_args[0], 1),
+                                  TRUE);
+                       fix_cpos;
+                       seen_disp_event = TRUE;
+                       break;
+                     case '@':       /* insert chars */
+                       /* XXX VTTEST says this is vt220, vt510 manual says vt102 */
+                       compatibility(VT102);
+                       insch(def(esc_args[0], 1));
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'P':       /* delete chars */
+                       compatibility(VT102);
+                       insch(-def(esc_args[0], 1));
+                       seen_disp_event = TRUE;
+                       break;
+                     case 'c':       /* terminal type query */
+                       compatibility(VT100);
+                       /* This is the response for a VT102 */
+                       ldisc_send(id_string, strlen(id_string));
+                       break;
+                     case 'n':       /* cursor position query */
+                       if (esc_args[0] == 6) {
+                           char buf[32];
+                           sprintf(buf, "\033[%d;%dR", curs.y + 1,
+                                   curs.x + 1);
+                           ldisc_send(buf, strlen(buf));
+                       } else if (esc_args[0] == 5) {
+                           ldisc_send("\033[0n", 4);
+                       }
+                       break;
+                     case 'h':       /* toggle modes to high */
+                     case ANSI_QUE('h'):
+                       compatibility(VT100);
+                       {
+                           int i;
+                           for (i = 0; i < esc_nargs; i++)
+                               toggle_mode(esc_args[i], esc_query, TRUE);
+                       }
+                       break;
+                     case 'l':       /* toggle modes to low */
+                     case ANSI_QUE('l'):
+                       compatibility(VT100);
+                       {
+                           int i;
+                           for (i = 0; i < esc_nargs; i++)
+                               toggle_mode(esc_args[i], esc_query, FALSE);
+                       }
+                       break;
+                     case 'g':       /* clear tabs */
+                       compatibility(VT100);
+                       if (esc_nargs == 1) {
+                           if (esc_args[0] == 0) {
+                               tabs[curs.x] = FALSE;
+                           } else if (esc_args[0] == 3) {
+                               int i;
+                               for (i = 0; i < cols; i++)
+                                   tabs[i] = FALSE;
+                           }
+                       }
+                       break;
+                     case 'r':       /* set scroll margins */
+                       compatibility(VT100);
+                       if (esc_nargs <= 2) {
+                           int top, bot;
+                           top = def(esc_args[0], 1) - 1;
+                           bot = (esc_nargs <= 1
+                                  || esc_args[1] ==
+                                  0 ? rows : def(esc_args[1], rows)) - 1;
+                           if (bot >= rows)
+                               bot = rows - 1;
+                           /* VTTEST Bug 9 - if region is less than 2 lines
+                            * don't change region.
+                            */
+                           if (bot - top > 0) {
+                               marg_t = top;
+                               marg_b = bot;
+                               curs.x = 0;
+                               /*
+                                * I used to think the cursor should be
+                                * placed at the top of the newly marginned
+                                * area. Apparently not: VMS TPU falls over
+                                * if so.
+                                *
+                                * Well actually it should for Origin mode - RDB
+                                */
+                               curs.y = (dec_om ? marg_t : 0);
+                               fix_cpos;
+                               seen_disp_event = TRUE;
+                           }
+                       }
+                       break;
+                     case 'm':       /* set graphics rendition */
+                       {
+                           /* 
+                            * A VT100 without the AVO only had one attribute, either
+                            * underline or reverse video depending on the cursor type,
+                            * this was selected by CSI 7m.
+                            *
+                            * case 2:
+                            *  This is sometimes DIM, eg on the GIGI and Linux
+                            * case 8:
+                            *  This is sometimes INVIS various ANSI.
+                            * case 21:
+                            *  This like 22 disables BOLD, DIM and INVIS
+                            *
+                            * The ANSI colours appear on any terminal that has colour
+                            * (obviously) but the interaction between sgr0 and the
+                            * colours varies but is usually related to the background
+                            * colour erase item.
+                            * The interaction between colour attributes and the mono
+                            * ones is also very implementation dependent.
+                            *
+                            * The 39 and 49 attributes are likely to be unimplemented.
+                            */
+                           int i;
+                           for (i = 0; i < esc_nargs; i++) {
+                               switch (def(esc_args[i], 0)) {
+                                 case 0:       /* restore defaults */
+                                   curr_attr = ATTR_DEFAULT;
+                                   break;
+                                 case 1:       /* enable bold */
+                                   compatibility(VT100AVO);
+                                   curr_attr |= ATTR_BOLD;
+                                   break;
+                                 case 21:      /* (enable double underline) */
+                                   compatibility(OTHER);
+                                 case 4:       /* enable underline */
+                                   compatibility(VT100AVO);
+                                   curr_attr |= ATTR_UNDER;
+                                   break;
+                                 case 5:       /* enable blink */
+                                   compatibility(VT100AVO);
+                                   curr_attr |= ATTR_BLINK;
+                                   break;
+                                 case 7:       /* enable reverse video */
+                                   curr_attr |= ATTR_REVERSE;
+                                   break;
+                                 case 10:      /* SCO acs off */
+                                   compatibility(SCOANSI);
+                                   sco_acs = 0; break;
+                                 case 11:      /* SCO acs on */
+                                   compatibility(SCOANSI);
+                                   sco_acs = 1; break;
+                                 case 12:      /* SCO acs on flipped */
+                                   compatibility(SCOANSI);
+                                   sco_acs = 2; break;
+                                 case 22:      /* disable bold */
+                                   compatibility2(OTHER, VT220);
+                                   curr_attr &= ~ATTR_BOLD;
+                                   break;
+                                 case 24:      /* disable underline */
+                                   compatibility2(OTHER, VT220);
+                                   curr_attr &= ~ATTR_UNDER;
+                                   break;
+                                 case 25:      /* disable blink */
+                                   compatibility2(OTHER, VT220);
+                                   curr_attr &= ~ATTR_BLINK;
+                                   break;
+                                 case 27:      /* disable reverse video */
+                                   compatibility2(OTHER, VT220);
+                                   curr_attr &= ~ATTR_REVERSE;
+                                   break;
+                                 case 30:
+                                 case 31:
+                                 case 32:
+                                 case 33:
+                                 case 34:
+                                 case 35:
+                                 case 36:
+                                 case 37:
+                                   /* foreground */
+                                   curr_attr &= ~ATTR_FGMASK;
+                                   curr_attr |=
+                                       (esc_args[i] - 30) << ATTR_FGSHIFT;
+                                   break;
+                                 case 39:      /* default-foreground */
+                                   curr_attr &= ~ATTR_FGMASK;
+                                   curr_attr |= ATTR_DEFFG;
+                                   break;
+                                 case 40:
+                                 case 41:
+                                 case 42:
+                                 case 43:
+                                 case 44:
+                                 case 45:
+                                 case 46:
+                                 case 47:
+                                   /* background */
+                                   curr_attr &= ~ATTR_BGMASK;
+                                   curr_attr |=
+                                       (esc_args[i] - 40) << ATTR_BGSHIFT;
+                                   break;
+                                 case 49:      /* default-background */
+                                   curr_attr &= ~ATTR_BGMASK;
+                                   curr_attr |= ATTR_DEFBG;
+                                   break;
+                               }
+                           }
+                           if (use_bce)
+                               erase_char = (' ' | ATTR_ASCII |
+                                            (curr_attr & 
+                                             (ATTR_FGMASK | ATTR_BGMASK)));
+                       }
+                       break;
+                     case 's':       /* save cursor */
+                       save_cursor(TRUE);
+                       break;
+                     case 'u':       /* restore cursor */
+                       save_cursor(FALSE);
+                       seen_disp_event = TRUE;
+                       break;
+                     case 't':       /* set page size - ie window height */
                        /*
-                        * I used to think the cursor should be
-                        * placed at the top of the newly marginned
-                        * area. Apparently not: VMS TPU falls over
-                        * if so.
+                        * VT340/VT420 sequence DECSLPP, DEC only allows values
+                        *  24/25/36/48/72/144 other emulators (eg dtterm) use
+                        * illegal values (eg first arg 1..9) for window changing 
+                        * and reports.
                         */
-                       curs_y = 0;
+                       compatibility(VT340TEXT);
+                       if (esc_nargs <= 1
+                           && (esc_args[0] < 1 || esc_args[0] >= 24)) {
+                           request_resize(cols, def(esc_args[0], 24), 0);
+                           deselect();
+                       }
+                       break;
+                     case 'S':
+                       compatibility(SCOANSI);
+                       scroll(marg_t, marg_b, def(esc_args[0], 1), TRUE);
                        fix_cpos;
+                       wrapnext = FALSE;
                        seen_disp_event = TRUE;
-                   }
-               }
-               break;
-             case 'm':                /* set graphics rendition */
-               {
-                   int i;
-                   for (i=0; i<esc_nargs; i++) {
-                       switch (def(esc_args[i], 0)) {
-                         case 0:      /* restore defaults */
-                           curr_attr = ATTR_DEFAULT; break;
-                         case 1:      /* enable bold */
-                           curr_attr |= ATTR_BOLD; break;
-                         case 4:      /* enable underline */
-                         case 21:     /* (enable double underline) */
-                           curr_attr |= ATTR_UNDER; break;
-                         case 7:      /* enable reverse video */
-                           curr_attr |= ATTR_REVERSE; break;
-                         case 22:     /* disable bold */
-                           curr_attr &= ~ATTR_BOLD; break;
-                         case 24:     /* disable underline */
-                           curr_attr &= ~ATTR_UNDER; break;
-                         case 27:     /* disable reverse video */
-                           curr_attr &= ~ATTR_REVERSE; break;
-                         case 30: case 31: case 32: case 33:
-                         case 34: case 35: case 36: case 37:
-                           /* foreground */
-                           curr_attr &= ~ATTR_FGMASK;
-                           curr_attr |= (esc_args[i] - 30) << ATTR_FGSHIFT;
+                       break;
+                     case 'T':
+                       compatibility(SCOANSI);
+                       scroll(marg_t, marg_b, -def(esc_args[0], 1), TRUE);
+                       fix_cpos;
+                       wrapnext = FALSE;
+                       seen_disp_event = TRUE;
+                       break;
+                     case ANSI('|', '*'):
+                       /* VT420 sequence DECSNLS
+                        * Set number of lines on screen
+                        * VT420 uses VGA like hardware and can support any size in
+                        * reasonable range (24..49 AIUI) with no default specified.
+                        */
+                       compatibility(VT420);
+                       if (esc_nargs == 1 && esc_args[0] > 0) {
+                           request_resize(cols,
+                                          def(esc_args[0], cfg.height),
+                                          0);
+                           deselect();
+                       }
+                       break;
+                     case ANSI('|', '$'):
+                       /* VT340/VT420 sequence DECSCPP
+                        * Set number of columns per page
+                        * Docs imply range is only 80 or 132, but I'll allow any.
+                        */
+                       compatibility(VT340TEXT);
+                       if (esc_nargs <= 1) {
+                           request_resize(def(esc_args[0], cfg.width),
+                                          rows, 0);
+                           deselect();
+                       }
+                       break;
+                     case 'X':       /* write N spaces w/o moving cursor */
+                       /* XXX VTTEST says this is vt220, vt510 manual says vt100 */
+                       compatibility(ANSIMIN);
+                       {
+                           int n = def(esc_args[0], 1);
+                           pos cursplus;
+                           unsigned long *p = cpos;
+                           if (n > cols - curs.x)
+                               n = cols - curs.x;
+                           cursplus = curs;
+                           cursplus.x += n;
+                           check_selection(curs, cursplus);
+                           while (n--)
+                               *p++ = erase_char;
+                           seen_disp_event = TRUE;
+                       }
+                       break;
+                     case 'x':       /* report terminal characteristics */
+                       compatibility(VT100);
+                       {
+                           char buf[32];
+                           int i = def(esc_args[0], 0);
+                           if (i == 0 || i == 1) {
+                               strcpy(buf, "\033[2;1;1;112;112;1;0x");
+                               buf[2] += i;
+                               ldisc_send(buf, 20);
+                           }
+                       }
+                       break;
+                     case 'Z':         /* BackTab for xterm */
+                       compatibility(OTHER);
+                       {
+                           int i = def(esc_args[0], 1);
+                           pos old_curs = curs;
+
+                           for(;i>0 && curs.x>0; i--) {
+                               do {
+                                   curs.x--;
+                               } while (curs.x >0 && !tabs[curs.x]);
+                           }
+                           fix_cpos;
+                           check_selection(old_curs, curs);
+                       }
+                       break;
+                     case ANSI('L', '='):
+                       compatibility(OTHER);
+                       use_bce = (esc_args[0] <= 0);
+                       erase_char = ERASE_CHAR;
+                       if (use_bce)
+                           erase_char = (' ' | ATTR_ASCII |
+                                        (curr_attr & 
+                                         (ATTR_FGMASK | ATTR_BGMASK)));
+                       break;
+                     case ANSI('E', '='):
+                       compatibility(OTHER);
+                       blink_is_real = (esc_args[0] >= 1);
+                       break;
+                     case ANSI('p', '"'):
+                       /* Allow the host to make this emulator a 'perfect' VT102.
+                        * This first appeared in the VT220, but we do need to get 
+                        * back to PuTTY mode so I won't check it.
+                        *
+                        * The arg in 40..42,50 are a PuTTY extension.
+                        * The 2nd arg, 8bit vs 7bit is not checked.
+                        *
+                        * Setting VT102 mode should also change the Fkeys to
+                        * generate PF* codes as a real VT102 has no Fkeys.
+                        * The VT220 does this, F11..F13 become ESC,BS,LF other Fkeys
+                        * send nothing.
+                        *
+                        * Note ESC c will NOT change this!
+                        */
+
+                       switch (esc_args[0]) {
+                         case 61:
+                           compatibility_level &= ~TM_VTXXX;
+                           compatibility_level |= TM_VT102;
                            break;
-                         case 39:     /* default-foreground */
-                           curr_attr &= ~ATTR_FGMASK;
-                           curr_attr |= ATTR_DEFFG;
+                         case 62:
+                           compatibility_level &= ~TM_VTXXX;
+                           compatibility_level |= TM_VT220;
                            break;
-                         case 40: case 41: case 42: case 43:
-                         case 44: case 45: case 46: case 47:
-                           /* background */
-                           curr_attr &= ~ATTR_BGMASK;
-                           curr_attr |= (esc_args[i] - 40) << ATTR_BGSHIFT;
+
+                         default:
+                           if (esc_args[0] > 60 && esc_args[0] < 70)
+                               compatibility_level |= TM_VTXXX;
                            break;
-                         case 49:     /* default-background */
-                           curr_attr &= ~ATTR_BGMASK;
-                           curr_attr |= ATTR_DEFBG;
+
+                         case 40:
+                           compatibility_level &= TM_VTXXX;
                            break;
+                         case 41:
+                           compatibility_level = TM_PUTTY;
+                           break;
+                         case 42:
+                           compatibility_level = TM_SCOANSI;
+                           break;
+
+                         case ARG_DEFAULT:
+                           compatibility_level = TM_PUTTY;
+                           break;
+                         case 50:
+                           break;
+                       }
+
+                       /* Change the response to CSI c */
+                       if (esc_args[0] == 50) {
+                           int i;
+                           char lbuf[64];
+                           strcpy(id_string, "\033[?");
+                           for (i = 1; i < esc_nargs; i++) {
+                               if (i != 1)
+                                   strcat(id_string, ";");
+                               sprintf(lbuf, "%d", esc_args[i]);
+                               strcat(id_string, lbuf);
+                           }
+                           strcat(id_string, "c");
                        }
+#if 0
+                       /* Is this a good idea ? 
+                        * Well we should do a soft reset at this point ...
+                        */
+                       if (!has_compat(VT420) && has_compat(VT100)) {
+                           if (reset_132)
+                               request_resize(132, 24, 1);
+                           else
+                               request_resize(80, 24, 1);
+                       }
+#endif
+                       break;
                    }
-               }
-               break;
-             case 's':                /* save cursor */
-               save_cursor (TRUE);
-               break;
-             case 'u':                /* restore cursor */
-               save_cursor (FALSE);
-               seen_disp_event = TRUE;
                break;
-             case 't':                /* set page size - ie window height */
-               request_resize (cols, def(esc_args[0], 24));
-               deselect();
-               break;
-             case 'X':                /* write N spaces w/o moving cursor */
-               {
-                   int n = def(esc_args[0], 1);
-                   unsigned long *p = cpos;
-                   if (n > cols - curs_x)
-                       n = cols - curs_x;
-                   check_selection (cpos, cpos+n);
-                   while (n--)
-                       *p++ = ERASE_CHAR;
-                   seen_disp_event = TRUE;
+             case SEEN_OSC:
+               osc_w = FALSE;
+               switch (c) {
+                 case 'P':            /* Linux palette sequence */
+                   termstate = SEEN_OSC_P;
+                   osc_strlen = 0;
+                   break;
+                 case 'R':            /* Linux palette reset */
+                   palette_reset();
+                   term_invalidate();
+                   termstate = TOPLEVEL;
+                   break;
+                 case 'W':            /* word-set */
+                   termstate = SEEN_OSC_W;
+                   osc_w = TRUE;
+                   break;
+                 case '0':
+                 case '1':
+                 case '2':
+                 case '3':
+                 case '4':
+                 case '5':
+                 case '6':
+                 case '7':
+                 case '8':
+                 case '9':
+                   esc_args[0] = 10 * esc_args[0] + c - '0';
+                   break;
+                 case 'L':
+                   /*
+                    * Grotty hack to support xterm and DECterm title
+                    * sequences concurrently.
+                    */
+                   if (esc_args[0] == 2) {
+                       esc_args[0] = 1;
+                       break;
+                   }
+                   /* else fall through */
+                 default:
+                   termstate = OSC_STRING;
+                   osc_strlen = 0;
                }
                break;
-             case 'x':                /* report terminal characteristics */
+             case OSC_STRING:
+               /*
+                * This OSC stuff is EVIL. It takes just one character to get into
+                * sysline mode and it's not initially obvious how to get out.
+                * So I've added CR and LF as string aborts.
+                * This shouldn't effect compatibility as I believe embedded 
+                * control characters are supposed to be interpreted (maybe?) 
+                * and they don't display anything useful anyway.
+                *
+                * -- RDB
+                */
+               if (c == '\n' || c == '\r') {
+                   termstate = TOPLEVEL;
+               } else if (c == 0234 || c == '\007') {
+                   /*
+                    * These characters terminate the string; ST and BEL
+                    * terminate the sequence and trigger instant
+                    * processing of it, whereas ESC goes back to SEEN_ESC
+                    * mode unless it is followed by \, in which case it is
+                    * synonymous with ST in the first place.
+                    */
+                   do_osc();
+                   termstate = TOPLEVEL;
+               } else if (c == '\033')
+                   termstate = OSC_MAYBE_ST;
+               else if (osc_strlen < OSC_STR_MAX)
+                   osc_string[osc_strlen++] = c;
+               break;
+             case SEEN_OSC_P:
                {
-                   char buf[32];
-                   int i = def(esc_args[0], 0);
-                   if (i == 0 || i == 1) {
-                       strcpy (buf, "\033[2;1;1;112;112;1;0x");
-                       buf[2] += i;
-                       ldisc->send (buf, 20);
+                   int max = (osc_strlen == 0 ? 21 : 16);
+                   int val;
+                   if (c >= '0' && c <= '9')
+                       val = c - '0';
+                   else if (c >= 'A' && c <= 'A' + max - 10)
+                       val = c - 'A' + 10;
+                   else if (c >= 'a' && c <= 'a' + max - 10)
+                       val = c - 'a' + 10;
+                   else {
+                       termstate = TOPLEVEL;
+                       break;
+                   }
+                   osc_string[osc_strlen++] = val;
+                   if (osc_strlen >= 7) {
+                       palette_set(osc_string[0],
+                                   osc_string[1] * 16 + osc_string[2],
+                                   osc_string[3] * 16 + osc_string[4],
+                                   osc_string[5] * 16 + osc_string[6]);
+                       term_invalidate();
+                       termstate = TOPLEVEL;
                    }
                }
                break;
-           }
-           break;
-         case SET_GL:
-         case SET_GR:
-           switch (c) {
-             case 'A':
-               cset_attr[termstate == SET_GL ? 0 : 1] = ATTR_GBCHR;
-               break;
-             case '0':
-               cset_attr[termstate == SET_GL ? 0 : 1] = ATTR_LINEDRW;
+             case SEEN_OSC_W:
+               switch (c) {
+                 case '0':
+                 case '1':
+                 case '2':
+                 case '3':
+                 case '4':
+                 case '5':
+                 case '6':
+                 case '7':
+                 case '8':
+                 case '9':
+                   esc_args[0] = 10 * esc_args[0] + c - '0';
+                   break;
+                 default:
+                   termstate = OSC_STRING;
+                   osc_strlen = 0;
+               }
                break;
-             default:                 /* specifically, 'B' */
-               cset_attr[termstate == SET_GL ? 0 : 1] = ATTR_ASCII;
+             case VT52_ESC:
+               termstate = TOPLEVEL;
+               seen_disp_event = TRUE;
+               switch (c) {
+                 case 'A':
+                   move(curs.x, curs.y - 1, 1);
+                   break;
+                 case 'B':
+                   move(curs.x, curs.y + 1, 1);
+                   break;
+                 case 'C':
+                   move(curs.x + 1, curs.y, 1);
+                   break;
+                 case 'D':
+                   move(curs.x - 1, curs.y, 1);
+                   break;
+                   /*
+                    * From the VT100 Manual
+                    * NOTE: The special graphics characters in the VT100
+                    *       are different from those in the VT52
+                    *
+                    * From VT102 manual:
+                    *       137 _  Blank             - Same
+                    *       140 `  Reserved          - Humm.
+                    *       141 a  Solid rectangle   - Similar
+                    *       142 b  1/                - Top half of fraction for the
+                    *       143 c  3/                - subscript numbers below.
+                    *       144 d  5/
+                    *       145 e  7/
+                    *       146 f  Degrees           - Same
+                    *       147 g  Plus or minus     - Same
+                    *       150 h  Right arrow
+                    *       151 i  Ellipsis (dots)
+                    *       152 j  Divide by
+                    *       153 k  Down arrow
+                    *       154 l  Bar at scan 0
+                    *       155 m  Bar at scan 1
+                    *       156 n  Bar at scan 2
+                    *       157 o  Bar at scan 3     - Similar
+                    *       160 p  Bar at scan 4     - Similar
+                    *       161 q  Bar at scan 5     - Similar
+                    *       162 r  Bar at scan 6     - Same
+                    *       163 s  Bar at scan 7     - Similar
+                    *       164 t  Subscript 0
+                    *       165 u  Subscript 1
+                    *       166 v  Subscript 2
+                    *       167 w  Subscript 3
+                    *       170 x  Subscript 4
+                    *       171 y  Subscript 5
+                    *       172 z  Subscript 6
+                    *       173 {  Subscript 7
+                    *       174 |  Subscript 8
+                    *       175 }  Subscript 9
+                    *       176 ~  Paragraph
+                    *
+                    */
+                 case 'F':
+                   cset_attr[cset = 0] = ATTR_LINEDRW;
+                   break;
+                 case 'G':
+                   cset_attr[cset = 0] = ATTR_ASCII;
+                   break;
+                 case 'H':
+                   move(0, 0, 0);
+                   break;
+                 case 'I':
+                   if (curs.y == 0)
+                       scroll(0, rows - 1, -1, TRUE);
+                   else if (curs.y > 0)
+                       curs.y--;
+                   fix_cpos;
+                   wrapnext = FALSE;
+                   break;
+                 case 'J':
+                   erase_lots(FALSE, FALSE, TRUE);
+                   disptop = 0;
+                   break;
+                 case 'K':
+                   erase_lots(TRUE, FALSE, TRUE);
+                   break;
+#if 0
+                 case 'V':
+                   /* XXX Print cursor line */
+                   break;
+                 case 'W':
+                   /* XXX Start controller mode */
+                   break;
+                 case 'X':
+                   /* XXX Stop controller mode */
+                   break;
+#endif
+                 case 'Y':
+                   termstate = VT52_Y1;
+                   break;
+                 case 'Z':
+                   ldisc_send("\033/Z", 3);
+                   break;
+                 case '=':
+                   app_keypad_keys = TRUE;
+                   break;
+                 case '>':
+                   app_keypad_keys = FALSE;
+                   break;
+                 case '<':
+                   /* XXX This should switch to VT100 mode not current or default
+                    *     VT mode. But this will only have effect in a VT220+
+                    *     emulation.
+                    */
+                   vt52_mode = FALSE;
+                   blink_is_real = cfg.blinktext;
+                   break;
+#if 0
+                 case '^':
+                   /* XXX Enter auto print mode */
+                   break;
+                 case '_':
+                   /* XXX Exit auto print mode */
+                   break;
+                 case ']':
+                   /* XXX Print screen */
+                   break;
+#endif
+
+#ifdef VT52_PLUS
+                 case 'E':
+                   /* compatibility(ATARI) */
+                   move(0, 0, 0);
+                   erase_lots(FALSE, FALSE, TRUE);
+                   disptop = 0;
+                   break;
+                 case 'L':
+                   /* compatibility(ATARI) */
+                   if (curs.y <= marg_b)
+                       scroll(curs.y, marg_b, -1, FALSE);
+                   break;
+                 case 'M':
+                   /* compatibility(ATARI) */
+                   if (curs.y <= marg_b)
+                       scroll(curs.y, marg_b, 1, TRUE);
+                   break;
+                 case 'b':
+                   /* compatibility(ATARI) */
+                   termstate = VT52_FG;
+                   break;
+                 case 'c':
+                   /* compatibility(ATARI) */
+                   termstate = VT52_BG;
+                   break;
+                 case 'd':
+                   /* compatibility(ATARI) */
+                   erase_lots(FALSE, TRUE, FALSE);
+                   disptop = 0;
+                   break;
+                 case 'e':
+                   /* compatibility(ATARI) */
+                   cursor_on = TRUE;
+                   break;
+                 case 'f':
+                   /* compatibility(ATARI) */
+                   cursor_on = FALSE;
+                   break;
+                   /* case 'j': Save cursor position - broken on ST */
+                   /* case 'k': Restore cursor position */
+                 case 'l':
+                   /* compatibility(ATARI) */
+                   erase_lots(TRUE, TRUE, TRUE);
+                   curs.x = 0;
+                   wrapnext = FALSE;
+                   fix_cpos;
+                   break;
+                 case 'o':
+                   /* compatibility(ATARI) */
+                   erase_lots(TRUE, TRUE, FALSE);
+                   break;
+                 case 'p':
+                   /* compatibility(ATARI) */
+                   curr_attr |= ATTR_REVERSE;
+                   break;
+                 case 'q':
+                   /* compatibility(ATARI) */
+                   curr_attr &= ~ATTR_REVERSE;
+                   break;
+                 case 'v':            /* wrap Autowrap on - Wyse style */
+                   /* compatibility(ATARI) */
+                   wrap = 1;
+                   break;
+                 case 'w':            /* Autowrap off */
+                   /* compatibility(ATARI) */
+                   wrap = 0;
+                   break;
+
+                 case 'R':
+                   /* compatibility(OTHER) */
+                   vt52_bold = FALSE;
+                   curr_attr = ATTR_DEFAULT;
+                   if (use_bce)
+                       erase_char = (' ' | ATTR_ASCII |
+                                    (curr_attr & 
+                                     (ATTR_FGMASK | ATTR_BGMASK)));
+                   break;
+                 case 'S':
+                   /* compatibility(VI50) */
+                   curr_attr |= ATTR_UNDER;
+                   break;
+                 case 'W':
+                   /* compatibility(VI50) */
+                   curr_attr &= ~ATTR_UNDER;
+                   break;
+                 case 'U':
+                   /* compatibility(VI50) */
+                   vt52_bold = TRUE;
+                   curr_attr |= ATTR_BOLD;
+                   break;
+                 case 'T':
+                   /* compatibility(VI50) */
+                   vt52_bold = FALSE;
+                   curr_attr &= ~ATTR_BOLD;
+                   break;
+#endif
+               }
                break;
-           }
-           termstate = TOPLEVEL;
-           break;
-         case SEEN_OSC:
-           osc_w = FALSE;
-           switch (c) {
-             case 'P':                /* Linux palette sequence */
-               termstate = SEEN_OSC_P;
-               osc_strlen = 0;
+             case VT52_Y1:
+               termstate = VT52_Y2;
+               move(curs.x, c - ' ', 0);
                break;
-             case 'R':                /* Linux palette reset */
-               palette_reset();
-               term_invalidate();
+             case VT52_Y2:
                termstate = TOPLEVEL;
+               move(c - ' ', curs.y, 0);
                break;
-             case 'W':                /* word-set */
-               termstate = SEEN_OSC_W;
-               osc_w = TRUE;
-               break;
-             case '0': case '1': case '2': case '3': case '4':
-             case '5': case '6': case '7': case '8': case '9':
-               esc_args[0] = 10 * esc_args[0] + c - '0';
+
+#ifdef VT52_PLUS
+             case VT52_FG:
+               termstate = TOPLEVEL;
+               curr_attr &= ~ATTR_FGMASK;
+               curr_attr &= ~ATTR_BOLD;
+               curr_attr |= (c & 0x7) << ATTR_FGSHIFT;
+               if ((c & 0x8) || vt52_bold)
+                   curr_attr |= ATTR_BOLD;
+
+               if (use_bce)
+                   erase_char = (' ' | ATTR_ASCII |
+                                (curr_attr & (ATTR_FGMASK | ATTR_BGMASK)));
                break;
-             case 'L':
-               /*
-                * Grotty hack to support xterm and DECterm title
-                * sequences concurrently.
-                */
-               if (esc_args[0] == 2) {
-                   esc_args[0] = 1;
-                   break;
-               }
-               /* else fall through */
-             default:
-               termstate = OSC_STRING;
-               osc_strlen = 0;
-           }
-           break;
-         case OSC_STRING:
-           if (c == 0234 || c == '\007') {
-               /*
-                * These characters terminate the string; ST and BEL
-                * terminate the sequence and trigger instant
-                * processing of it, whereas ESC goes back to SEEN_ESC
-                * mode unless it is followed by \, in which case it is
-                * synonymous with ST in the first place.
-                */
-               do_osc();
+             case VT52_BG:
                termstate = TOPLEVEL;
-           } else if (c == '\033')
-                   termstate = OSC_MAYBE_ST;
-           else if (osc_strlen < OSC_STR_MAX)
-               osc_string[osc_strlen++] = c;
-           break;
-         case SEEN_OSC_P:
-           {
-               int max = (osc_strlen == 0 ? 21 : 16);
-               int val;
-               if (c >= '0' && c <= '9')
-                   val = c - '0';
-               else if (c >= 'A' && c <= 'A'+max-10)
-                   val = c - 'A' + 10;
-               else if (c >= 'a' && c <= 'a'+max-10)
-                   val = c - 'a' + 10;
-               else
-                   termstate = TOPLEVEL;
-               osc_string[osc_strlen++] = val;
-               if (osc_strlen >= 7) {
-                   palette_set (osc_string[0],
-                                osc_string[1] * 16 + osc_string[2],
-                                osc_string[3] * 16 + osc_string[4],
-                                osc_string[5] * 16 + osc_string[6]);
-                   term_invalidate();
-                   termstate = TOPLEVEL;
-               }
-           }
-           break;
-         case SEEN_OSC_W:
-           switch (c) {
-             case '0': case '1': case '2': case '3': case '4':
-             case '5': case '6': case '7': case '8': case '9':
-               esc_args[0] = 10 * esc_args[0] + c - '0';
+               curr_attr &= ~ATTR_BGMASK;
+               curr_attr &= ~ATTR_BLINK;
+               curr_attr |= (c & 0x7) << ATTR_BGSHIFT;
+
+               /* Note: bold background */
+               if (c & 0x8)
+                   curr_attr |= ATTR_BLINK;
+
+               if (use_bce)
+                   erase_char = (' ' | ATTR_ASCII |
+                                (curr_attr & (ATTR_FGMASK | ATTR_BGMASK)));
                break;
-             default:
-               termstate = OSC_STRING;
-               osc_strlen = 0;
-           }
-           break;
-         case SEEN_ESCHASH:
-           if (c == '8') {
-               unsigned long *p = scrtop;
-               int n = rows * (cols+1);
-               while (n--)
-                   *p++ = ATTR_DEFAULT | 'E';
-               disptop = scrtop;
-               seen_disp_event = TRUE;
-               check_selection (scrtop, scrtop + rows * (cols+1));
+#endif
+             default: break;          /* placate gcc warning about enum use */
            }
-           termstate = TOPLEVEL;
-           break;
+       if (selstate != NO_SELECTION) {
+           pos cursplus = curs;
+           incpos(cursplus);
+           check_selection(curs, cursplus);
        }
-       check_selection (cpos, cpos+1);
     }
-       
-    if (nl_count > MAXNL)
-       term_update();
+    inbuf_head = 0;
 }
 
+#if 0
 /*
  * Compare two lines to determine whether they are sufficiently
  * alike to scroll-optimise one to the other. Return the degree of
  * similarity.
  */
-static int linecmp (unsigned long *a, unsigned long *b) {
+static int linecmp(unsigned long *a, unsigned long *b)
+{
     int i, n;
 
-    for (i=n=0; i < cols; i++)
+    for (i = n = 0; i < cols; i++)
        n += (*a++ == *b++);
     return n;
 }
+#endif
 
 /*
  * Given a context, update the window. Out of paranoia, we don't
  * allow WM_PAINT responses to do scrolling optimisations.
  */
-static void do_paint (Context ctx, int may_optimise){ 
-    int i, j, start, our_curs_y;
-    unsigned long attr, rv, cursor;
+static void do_paint(Context ctx, int may_optimise)
+{
+    int i, j, our_curs_y;
+    unsigned long rv, cursor;
+    pos scrpos;
     char ch[1024];
+    long cursor_background = ERASE_CHAR;
+    long ticks;
 
-    cursor = (has_focus ? ATTR_ACTCURS : ATTR_PASCURS);
-    rv = (rvideo ? ATTR_REVERSE : 0);
-    our_curs_y = curs_y + (scrtop - disptop) / (cols+1);
-
-    for (i=0; i<rows; i++) {
-       int idx = i*(cols+1);
-       for (j=0; j<=cols; j++,idx++) {
-           unsigned long *d = disptop+idx;
-           wanttext[idx] = ((*d ^ rv
-                             ^ (selstart <= d && d < selend ?
-                                ATTR_REVERSE : 0)) |
-                            (i==our_curs_y && j==curs_x ? cursor : 0));
-       }
+    /*
+     * Check the visual bell state.
+     */
+    if (in_vbell) {
+       ticks = GetTickCount();
+       if (ticks - vbell_timeout >= 0)
+           in_vbell = FALSE;
     }
 
-    /*
-     * We would perform scrolling optimisations in here, if they
-     * didn't have a nasty tendency to cause the whole sodding
-     * program to hang for a second at speed-critical moments.
-     * We'll leave it well alone...
+    rv = (!rvideo ^ !in_vbell ? ATTR_REVERSE : 0);
+
+    /* Depends on:
+     * screen array, disptop, scrtop,
+     * selection, rv, 
+     * cfg.blinkpc, blink_is_real, tblinker, 
+     * curs.y, curs.x, blinker, cfg.blink_cur, cursor_on, has_focus, wrapnext
      */
 
-    for (i=0; i<rows; i++) {
-       int idx = i*(cols+1);
-       start = -1;
-       for (j=0; j<=cols; j++,idx++) {
-           unsigned long t = wanttext[idx];
-           int needs_update = (j < cols && t != disptext[idx]);
-           int keep_going = (start != -1 && needs_update &&
-                             (t & ATTR_MASK) == attr &&
-                             j-start < sizeof(ch));
-           if (start != -1 && !keep_going) {
-               do_text (ctx, start, i, ch, j-start, attr);
-               start = -1;
+    /* Has the cursor position or type changed ? */
+    if (cursor_on) {
+       if (has_focus) {
+           if (blinker || !cfg.blink_cur)
+               cursor = TATTR_ACTCURS;
+           else
+               cursor = 0;
+       } else
+           cursor = TATTR_PASCURS;
+       if (wrapnext)
+           cursor |= TATTR_RIGHTCURS;
+    } else
+       cursor = 0;
+    our_curs_y = curs.y - disptop;
+
+    if (dispcurs && (curstype != cursor ||
+                    dispcurs !=
+                    disptext + our_curs_y * (cols + 1) + curs.x)) {
+       if (dispcurs > disptext && (dispcurs[-1] & ATTR_WIDE))
+           dispcurs[-1] |= ATTR_INVALID;
+       if ((*dispcurs & ATTR_WIDE))
+           dispcurs[1] |= ATTR_INVALID;
+       *dispcurs |= ATTR_INVALID;
+       curstype = 0;
+    }
+    dispcurs = NULL;
+
+    /* The normal screen data */
+    for (i = 0; i < rows; i++) {
+       unsigned long *ldata;
+       int lattr;
+       int idx, dirty_line, dirty_run;
+       unsigned long attr = 0;
+       int updated_line = 0;
+       int start = 0;
+       int ccount = 0;
+       int last_run_dirty = 0;
+
+       scrpos.y = i + disptop;
+       ldata = lineptr(scrpos.y);
+       lattr = (ldata[cols] & LATTR_MODE);
+
+       idx = i * (cols + 1);
+       dirty_run = dirty_line = (ldata[cols] != disptext[idx + cols]);
+       disptext[idx + cols] = ldata[cols];
+
+       for (j = 0; j < cols; j++, idx++) {
+           unsigned long tattr, tchar;
+           unsigned long *d = ldata + j;
+           int break_run;
+           scrpos.x = j;
+
+           tchar = (*d & (CHAR_MASK | CSET_MASK));
+           tattr = (*d & (ATTR_MASK ^ CSET_MASK));
+           switch (tchar & CSET_MASK) {
+             case ATTR_ASCII:
+               tchar = unitab_line[tchar & 0xFF];
+               break;
+             case ATTR_LINEDRW:
+               tchar = unitab_xterm[tchar & 0xFF];
+               break;
+             case ATTR_SCOACS:  
+               tchar = unitab_scoacs[tchar&0xFF]; 
+               break;
+           }
+           tattr |= (tchar & CSET_MASK);
+           tchar &= CHAR_MASK;
+
+           /* Video reversing things */
+           tattr = (tattr ^ rv
+                    ^ (posle(selstart, scrpos) &&
+                       poslt(scrpos, selend) ? ATTR_REVERSE : 0));
+
+           /* 'Real' blinking ? */
+           if (blink_is_real && (tattr & ATTR_BLINK)) {
+               if (has_focus && tblinker) {
+                   tchar = ' ';
+                   tattr &= ~CSET_MASK;
+                   tattr |= ATTR_ACP;
+               }
+               tattr &= ~ATTR_BLINK;
+           }
+
+           /* Cursor here ? Save the 'background' */
+           if (i == our_curs_y && j == curs.x) {
+               cursor_background = tattr | tchar;
+               dispcurs = disptext + idx;
+           }
+
+           if ((disptext[idx] ^ tattr) & ATTR_WIDE)
+               dirty_line = TRUE;
+
+           break_run = (tattr != attr || j - start >= sizeof(ch));
+
+           /* Special hack for VT100 Linedraw glyphs */
+           if ((attr & CSET_MASK) == 0x2300 && tchar >= 0xBA
+               && tchar <= 0xBD) break_run = TRUE;
+
+           if (!dbcs_screenfont && !dirty_line) {
+               if ((tchar | tattr) == disptext[idx])
+                   break_run = TRUE;
+               else if (!dirty_run && ccount == 1)
+                   break_run = TRUE;
            }
-           if (needs_update) {
-               if (start == -1) {
-                   start = j;
-                   attr = t & ATTR_MASK;
+
+           if (break_run) {
+               if ((dirty_run || last_run_dirty) && ccount > 0) {
+                   do_text(ctx, start, i, ch, ccount, attr, lattr);
+                   updated_line = 1;
+               }
+               start = j;
+               ccount = 0;
+               attr = tattr;
+               if (dbcs_screenfont)
+                   last_run_dirty = dirty_run;
+               dirty_run = dirty_line;
+           }
+
+           if ((tchar | tattr) != disptext[idx])
+               dirty_run = TRUE;
+           ch[ccount++] = (char) tchar;
+           disptext[idx] = tchar | tattr;
+
+           /* If it's a wide char step along to the next one. */
+           if (tattr & ATTR_WIDE) {
+               if (++j < cols) {
+                   idx++;
+                   d++;
+                   /* Cursor is here ? Ouch! */
+                   if (i == our_curs_y && j == curs.x) {
+                       cursor_background = *d;
+                       dispcurs = disptext + idx;
+                   }
+                   if (disptext[idx] != *d)
+                       dirty_run = TRUE;
+                   disptext[idx] = *d;
                }
-               ch[j-start] = (char) (t & CHAR_MASK);
            }
-           disptext[idx] = t;
        }
+       if (dirty_run && ccount > 0) {
+           do_text(ctx, start, i, ch, ccount, attr, lattr);
+           updated_line = 1;
+       }
+
+       /* Cursor on this line ? (and changed) */
+       if (i == our_curs_y && (curstype != cursor || updated_line)) {
+           ch[0] = (char) (cursor_background & CHAR_MASK);
+           attr = (cursor_background & ATTR_MASK) | cursor;
+           do_cursor(ctx, curs.x, i, ch, 1, attr, lattr);
+           curstype = cursor;
+       }
+    }
+}
+
+/*
+ * Flick the switch that says if blinking things should be shown or hidden.
+ */
+
+void term_blink(int flg)
+{
+    static long last_blink = 0;
+    static long last_tblink = 0;
+    long now, blink_diff;
+
+    now = GetTickCount();
+    blink_diff = now - last_tblink;
+
+    /* Make sure the text blinks no more than 2Hz */
+    if (blink_diff < 0 || blink_diff > 450) {
+       last_tblink = now;
+       tblinker = !tblinker;
+    }
+
+    if (flg) {
+       blinker = 1;
+       last_blink = now;
+       return;
     }
+
+    blink_diff = now - last_blink;
+
+    /* Make sure the cursor blinks no faster than GetCaretBlinkTime() */
+    if (blink_diff >= 0 && blink_diff < (long) GetCaretBlinkTime())
+       return;
+
+    last_blink = now;
+    blinker = !blinker;
 }
 
 /*
  * Invalidate the whole screen so it will be repainted in full.
  */
-void term_invalidate(void) {
+void term_invalidate(void)
+{
     int i;
 
-    for (i=0; i<rows*(cols+1); i++)
+    for (i = 0; i < rows * (cols + 1); i++)
        disptext[i] = ATTR_INVALID;
 }
 
 /*
  * Paint the window in response to a WM_PAINT message.
  */
-void term_paint (Context ctx, int l, int t, int r, int b) {
+void term_paint(Context ctx, int l, int t, int r, int b)
+{
     int i, j, left, top, right, bottom;
 
     left = l / font_width;
     right = (r - 1) / font_width;
     top = t / font_height;
     bottom = (b - 1) / font_height;
-    for (i = top; i <= bottom && i < rows ; i++)
-      for (j = left; j <= right && j < cols ; j++)
-           disptext[i*(cols+1)+j] = ATTR_INVALID;
+    for (i = top; i <= bottom && i < rows; i++) {
+       if ((disptext[i * (cols + 1) + cols] & LATTR_MODE) == LATTR_NORM)
+           for (j = left; j <= right && j < cols; j++)
+               disptext[i * (cols + 1) + j] = ATTR_INVALID;
+       else
+           for (j = left / 2; j <= right / 2 + 1 && j < cols; j++)
+               disptext[i * (cols + 1) + j] = ATTR_INVALID;
+    }
 
-    do_paint (ctx, FALSE);
+    /* This should happen soon enough, also for some reason it sometimes 
+     * fails to actually do anything when re-sizing ... painting the wrong
+     * window perhaps ?
+     do_paint (ctx, FALSE);
+     */
 }
 
 /*
@@ -1241,30 +2717,266 @@ void term_paint (Context ctx, int l, int t, int r, int b) {
  * to denote it is relative to the end, and 0 to denote that it is
  * relative to the current position.
  */
-void term_scroll (int rel, int where) {
-    int n = where * (cols+1);
+void term_scroll(int rel, int where)
+{
+    int sbtop = -count234(scrollback);
 
-    disptop = (rel < 0 ? scrtop :
-              rel > 0 ? sbtop : disptop) + n;
+    disptop = (rel < 0 ? 0 : rel > 0 ? sbtop : disptop) + where;
     if (disptop < sbtop)
        disptop = sbtop;
-    if (disptop > scrtop)
-       disptop = scrtop;
+    if (disptop > 0)
+       disptop = 0;
     update_sbar();
     term_update();
 }
 
+static void clipme(pos top, pos bottom)
+{
+    wchar_t *workbuf;
+    wchar_t *wbptr;                   /* where next char goes within workbuf */
+    int wblen = 0;                    /* workbuf len */
+    int buflen;                               /* amount of memory allocated to workbuf */
+
+    buflen = 5120;                    /* Default size */
+    workbuf = smalloc(buflen * sizeof(wchar_t));
+    wbptr = workbuf;                  /* start filling here */
+
+    while (poslt(top, bottom)) {
+       int nl = FALSE;
+       unsigned long *ldata = lineptr(top.y);
+       pos nlpos;
+
+       nlpos.y = top.y;
+       nlpos.x = cols;
+
+       if (!(ldata[cols] & LATTR_WRAPPED)) {
+           while (((ldata[nlpos.x - 1] & 0xFF) == 0x20 ||
+                   (DIRECT_CHAR(ldata[nlpos.x - 1]) &&
+                    (ldata[nlpos.x - 1] & CHAR_MASK) == 0x20))
+                  && poslt(top, nlpos))
+               decpos(nlpos);
+           if (poslt(nlpos, bottom))
+               nl = TRUE;
+       }
+       while (poslt(top, bottom) && poslt(top, nlpos)) {
+#if 0
+           char cbuf[16], *p;
+           sprintf(cbuf, "<U+%04x>", (ldata[top.x] & 0xFFFF));
+#else
+           wchar_t cbuf[16], *p;
+           int uc = (ldata[top.x] & 0xFFFF);
+           int set, c;
+
+           if (uc == UCSWIDE) {
+               top.x++;
+               continue;
+           }
+
+           switch (uc & CSET_MASK) {
+             case ATTR_LINEDRW:
+               if (!cfg.rawcnp) {
+                   uc = unitab_xterm[uc & 0xFF];
+                   break;
+               }
+             case ATTR_ASCII:
+               uc = unitab_line[uc & 0xFF];
+               break;
+             case ATTR_SCOACS:  
+               uc = unitab_scoacs[uc&0xFF]; 
+               break;
+           }
+           switch (uc & CSET_MASK) {
+             case ATTR_ACP:
+               uc = unitab_font[uc & 0xFF];
+               break;
+             case ATTR_OEMCP:
+               uc = unitab_oemcp[uc & 0xFF];
+               break;
+           }
+
+           set = (uc & CSET_MASK);
+           c = (uc & CHAR_MASK);
+           cbuf[0] = uc;
+           cbuf[1] = 0;
+
+           if (DIRECT_FONT(uc)) {
+               if (c >= ' ' && c != 0x7F) {
+                   unsigned char buf[4];
+                   WCHAR wbuf[4];
+                   int rv;
+                   if (IsDBCSLeadByteEx(font_codepage, (BYTE) c)) {
+                       buf[0] = c;
+                       buf[1] = (unsigned char) ldata[top.x + 1];
+                       rv = MultiByteToWideChar(font_codepage,
+                                                0, buf, 2, wbuf, 4);
+                       top.x++;
+                   } else {
+                       buf[0] = c;
+                       rv = MultiByteToWideChar(font_codepage,
+                                                0, buf, 1, wbuf, 4);
+                   }
+
+                   if (rv > 0) {
+                       memcpy(cbuf, wbuf, rv * sizeof(wchar_t));
+                       cbuf[rv] = 0;
+                   }
+               }
+           }
+#endif
+
+           for (p = cbuf; *p; p++) {
+               /* Enough overhead for trailing NL and nul */
+               if (wblen >= buflen - 16) {
+                   workbuf =
+                       srealloc(workbuf,
+                                sizeof(wchar_t) * (buflen += 100));
+                   wbptr = workbuf + wblen;
+               }
+               wblen++;
+               *wbptr++ = *p;
+           }
+           top.x++;
+       }
+       if (nl) {
+           int i;
+           for (i = 0; i < sel_nl_sz; i++) {
+               wblen++;
+               *wbptr++ = sel_nl[i];
+           }
+       }
+       top.y++;
+       top.x = 0;
+    }
+    wblen++;
+    *wbptr++ = 0;
+    write_clip(workbuf, wblen, FALSE); /* transfer to clipboard */
+    if (buflen > 0)                   /* indicates we allocated this buffer */
+       sfree(workbuf);
+}
+
+void term_copyall(void)
+{
+    pos top;
+    top.y = -count234(scrollback);
+    top.x = 0;
+    clipme(top, curs);
+}
+
+/*
+ * The wordness array is mainly for deciding the disposition of the US-ASCII 
+ * characters.
+ */
+static int wordtype(int uc)
+{
+    static struct {
+       int start, end, ctype;
+    } *wptr, ucs_words[] = {
+       {
+       128, 160, 0}, {
+       161, 191, 1}, {
+       215, 215, 1}, {
+       247, 247, 1}, {
+       0x037e, 0x037e, 1},            /* Greek question mark */
+       {
+       0x0387, 0x0387, 1},            /* Greek ano teleia */
+       {
+       0x055a, 0x055f, 1},            /* Armenian punctuation */
+       {
+       0x0589, 0x0589, 1},            /* Armenian full stop */
+       {
+       0x0700, 0x070d, 1},            /* Syriac punctuation */
+       {
+       0x104a, 0x104f, 1},            /* Myanmar punctuation */
+       {
+       0x10fb, 0x10fb, 1},            /* Georgian punctuation */
+       {
+       0x1361, 0x1368, 1},            /* Ethiopic punctuation */
+       {
+       0x166d, 0x166e, 1},            /* Canadian Syl. punctuation */
+       {
+       0x17d4, 0x17dc, 1},            /* Khmer punctuation */
+       {
+       0x1800, 0x180a, 1},            /* Mongolian punctuation */
+       {
+       0x2000, 0x200a, 0},            /* Various spaces */
+       {
+       0x2070, 0x207f, 2},            /* superscript */
+       {
+       0x2080, 0x208f, 2},            /* subscript */
+       {
+       0x200b, 0x27ff, 1},            /* punctuation and symbols */
+       {
+       0x3000, 0x3000, 0},            /* ideographic space */
+       {
+       0x3001, 0x3020, 1},            /* ideographic punctuation */
+       {
+       0x303f, 0x309f, 3},            /* Hiragana */
+       {
+       0x30a0, 0x30ff, 3},            /* Katakana */
+       {
+       0x3300, 0x9fff, 3},            /* CJK Ideographs */
+       {
+       0xac00, 0xd7a3, 3},            /* Hangul Syllables */
+       {
+       0xf900, 0xfaff, 3},            /* CJK Ideographs */
+       {
+       0xfe30, 0xfe6b, 1},            /* punctuation forms */
+       {
+       0xff00, 0xff0f, 1},            /* half/fullwidth ASCII */
+       {
+       0xff1a, 0xff20, 1},            /* half/fullwidth ASCII */
+       {
+       0xff3b, 0xff40, 1},            /* half/fullwidth ASCII */
+       {
+       0xff5b, 0xff64, 1},            /* half/fullwidth ASCII */
+       {
+       0xfff0, 0xffff, 0},            /* half/fullwidth ASCII */
+       {
+       0, 0, 0}
+    };
+
+    uc &= (CSET_MASK | CHAR_MASK);
+
+    switch (uc & CSET_MASK) {
+      case ATTR_LINEDRW:
+       uc = unitab_xterm[uc & 0xFF];
+       break;
+      case ATTR_ASCII:
+       uc = unitab_line[uc & 0xFF];
+       break;
+      case ATTR_SCOACS:  
+       uc = unitab_scoacs[uc&0xFF]; 
+       break;
+    }
+    switch (uc & CSET_MASK) {
+      case ATTR_ACP:
+       uc = unitab_font[uc & 0xFF];
+       break;
+      case ATTR_OEMCP:
+       uc = unitab_oemcp[uc & 0xFF];
+       break;
+    }
+
+    if (uc < 0x80)
+       return wordness[uc];
+
+    for (wptr = ucs_words; wptr->start; wptr++) {
+       if (uc >= wptr->start && uc <= wptr->end)
+           return wptr->ctype;
+    }
+
+    return 2;
+}
+
 /*
  * Spread the selection outwards according to the selection mode.
  */
-static unsigned long *sel_spread_half (unsigned long *p, int dir) {
-    unsigned long *linestart, *lineend;
-    int x;
+static pos sel_spread_half(pos p, int dir)
+{
+    unsigned long *ldata;
     short wvalue;
 
-    x = (p - text) % (cols+1);
-    linestart = p - x;
-    lineend = linestart + cols;
+    ldata = lineptr(p.y);
 
     switch (selmode) {
       case SM_CHAR:
@@ -1272,14 +2984,14 @@ static unsigned long *sel_spread_half (unsigned long *p, int dir) {
         * In this mode, every character is a separate unit, except
         * for runs of spaces at the end of a non-wrapping line.
         */
-       if (!(linestart[cols] & ATTR_WRAPPED)) {
-           unsigned long *q = lineend;
-           while (q > linestart && (q[-1] & CHAR_MASK) == 0x20)
+       if (!(ldata[cols] & LATTR_WRAPPED)) {
+           unsigned long *q = ldata + cols;
+           while (q > ldata && (q[-1] & CHAR_MASK) == 0x20)
                q--;
-           if (q == lineend)
+           if (q == ldata + cols)
                q--;
-           if (p >= q)
-               p = (dir == -1 ? q : lineend - 1);
+           if (p.x >= q - ldata)
+               p.x = (dir == -1 ? q - ldata : cols - 1);
        }
        break;
       case SM_WORD:
@@ -1287,157 +2999,383 @@ static unsigned long *sel_spread_half (unsigned long *p, int dir) {
         * In this mode, the units are maximal runs of characters
         * whose `wordness' has the same value.
         */
-       wvalue = wordness[*p & CHAR_MASK];
+       wvalue = wordtype(ldata[p.x]);
        if (dir == +1) {
-           while (p < lineend && wordness[p[1] & CHAR_MASK] == wvalue)
-               p++;
+           while (p.x < cols && wordtype(ldata[p.x + 1]) == wvalue)
+               p.x++;
        } else {
-           while (p > linestart && wordness[p[-1] & CHAR_MASK] == wvalue)
-               p--;
+           while (p.x > 0 && wordtype(ldata[p.x - 1]) == wvalue)
+               p.x--;
        }
        break;
       case SM_LINE:
        /*
         * In this mode, every line is a unit.
         */
-       p = (dir == -1 ? linestart : lineend - 1);
+       p.x = (dir == -1 ? 0 : cols - 1);
        break;
     }
     return p;
 }
 
-static void sel_spread (void) {
-    selstart = sel_spread_half (selstart, -1);
-    selend = sel_spread_half (selend - 1, +1) + 1;
+static void sel_spread(void)
+{
+    selstart = sel_spread_half(selstart, -1);
+    decpos(selend);
+    selend = sel_spread_half(selend, +1);
+    incpos(selend);
 }
 
-void term_mouse (Mouse_Button b, Mouse_Action a, int x, int y) {
-    unsigned long *selpoint;
-    
-    if (y<0) y = 0;
-    if (y>=rows) y = rows-1;
-    if (x<0) {
-        if (y > 0) {
-            x = cols-1;
-            y--;
-        } else
-            x = 0;
+void term_do_paste(void)
+{
+    wchar_t *data;
+    int len;
+
+    get_clip(&data, &len);
+    if (data) {
+        wchar_t *p, *q;
+
+        if (paste_buffer)
+            sfree(paste_buffer);
+        paste_pos = paste_hold = paste_len = 0;
+        paste_buffer = smalloc(len * sizeof(wchar_t));
+
+        p = q = data;
+        while (p < data + len) {
+            while (p < data + len &&
+                   !(p <= data + len - sel_nl_sz &&
+                     !memcmp(p, sel_nl, sizeof(sel_nl))))
+                p++;
+
+            {
+                int i;
+                for (i = 0; i < p - q; i++) {
+                    paste_buffer[paste_len++] = q[i];
+                }
+            }
+
+            if (p <= data + len - sel_nl_sz &&
+                !memcmp(p, sel_nl, sizeof(sel_nl))) {
+                paste_buffer[paste_len++] = '\r';
+                p += sel_nl_sz;
+            }
+            q = p;
+        }
+
+        /* Assume a small paste will be OK in one go. */
+        if (paste_len < 256) {
+            luni_send(paste_buffer, paste_len);
+            if (paste_buffer)
+                sfree(paste_buffer);
+            paste_buffer = 0;
+            paste_pos = paste_hold = paste_len = 0;
+        }
     }
-    if (x>=cols) x = cols-1;
+    get_clip(NULL, NULL);
+}
 
-    selpoint = disptop + y * (cols+1) + x;
+void term_mouse(Mouse_Button b, Mouse_Action a, int x, int y,
+               int shift, int ctrl)
+{
+    pos selpoint;
+    unsigned long *ldata;
 
-    if (b == MB_SELECT && a == MA_CLICK) {
+    if (y < 0)
+       y = 0;
+    if (y >= rows)
+       y = rows - 1;
+    if (x < 0) {
+       if (y > 0) {
+           x = cols - 1;
+           y--;
+       } else
+           x = 0;
+    }
+    if (x >= cols)
+       x = cols - 1;
+
+    selpoint.y = y + disptop;
+    selpoint.x = x;
+    ldata = lineptr(selpoint.y);
+    if ((ldata[cols] & LATTR_MODE) != LATTR_NORM)
+       selpoint.x /= 2;
+
+    if (xterm_mouse) {
+       int encstate = 0, r, c;
+       char abuf[16];
+       static int is_down = 0;
+
+       switch (b) {
+         case MBT_LEFT:
+           encstate = 0x20;           /* left button down */
+           break;
+         case MBT_MIDDLE:
+           encstate = 0x21;
+           break;
+         case MBT_RIGHT:
+           encstate = 0x22;
+           break;
+         case MBT_WHEEL_UP:
+           encstate = 0x60;
+           break;
+         case MBT_WHEEL_DOWN:
+           encstate = 0x61;
+           break;
+         default: break;              /* placate gcc warning about enum use */
+       }
+       switch (a) {
+         case MA_DRAG:
+           if (xterm_mouse == 1)
+               return;
+           encstate += 0x20;
+           break;
+         case MA_RELEASE:
+           encstate = 0x23;
+           is_down = 0;
+           break;
+         case MA_CLICK:
+           if (is_down == b)
+               return;
+           is_down = b;
+           break;
+         default: break;              /* placate gcc warning about enum use */
+       }
+       if (shift)
+           encstate += 0x04;
+       if (ctrl)
+           encstate += 0x10;
+       r = y + 33;
+       c = x + 33;
+
+       sprintf(abuf, "\033[M%c%c%c", encstate, c, r);
+       ldisc_send(abuf, 6);
+       return;
+    }
+
+    b = translate_button(b);
+
+    if (b == MBT_SELECT && a == MA_CLICK) {
        deselect();
        selstate = ABOUT_TO;
        selanchor = selpoint;
        selmode = SM_CHAR;
-    } else if (b == MB_SELECT && (a == MA_2CLK || a == MA_3CLK)) {
+    } else if (b == MBT_SELECT && (a == MA_2CLK || a == MA_3CLK)) {
        deselect();
        selmode = (a == MA_2CLK ? SM_WORD : SM_LINE);
        selstate = DRAGGING;
        selstart = selanchor = selpoint;
-       selend = selstart + 1;
+       selend = selstart;
+       incpos(selend);
        sel_spread();
-    } else if ((b == MB_SELECT && a == MA_DRAG) ||
-              (b == MB_EXTEND && a != MA_RELEASE)) {
-       if (selstate == ABOUT_TO && selanchor == selpoint)
+    } else if ((b == MBT_SELECT && a == MA_DRAG) ||
+              (b == MBT_EXTEND && a != MA_RELEASE)) {
+       if (selstate == ABOUT_TO && poseq(selanchor, selpoint))
            return;
-       if (b == MB_EXTEND && a != MA_DRAG && selstate == SELECTED) {
-           if (selpoint-selstart < (selend-selstart)/2)
-               selanchor = selend - 1;
-           else
+       if (b == MBT_EXTEND && a != MA_DRAG && selstate == SELECTED) {
+           if (posdiff(selpoint, selstart) <
+               posdiff(selend, selstart) / 2) {
+               selanchor = selend;
+               decpos(selanchor);
+           } else {
                selanchor = selstart;
+           }
            selstate = DRAGGING;
        }
        if (selstate != ABOUT_TO && selstate != DRAGGING)
            selanchor = selpoint;
        selstate = DRAGGING;
-       if (selpoint < selanchor) {
+       if (poslt(selpoint, selanchor)) {
            selstart = selpoint;
-           selend = selanchor + 1;
+           selend = selanchor;
+           incpos(selend);
        } else {
            selstart = selanchor;
-           selend = selpoint + 1;
+           selend = selpoint;
+           incpos(selend);
        }
        sel_spread();
-    } else if ((b == MB_SELECT || b == MB_EXTEND) && a == MA_RELEASE) {
+    } else if ((b == MBT_SELECT || b == MBT_EXTEND) && a == MA_RELEASE) {
        if (selstate == DRAGGING) {
            /*
             * We've completed a selection. We now transfer the
             * data to the clipboard.
             */
-           unsigned char *p = selspace;
-           unsigned long *q = selstart;
-
-           while (q < selend) {
-               int nl = FALSE;
-               unsigned long *lineend = q - (q-text) % (cols+1) + cols;
-               unsigned long *nlpos = lineend;
-
-               if (!(*nlpos & ATTR_WRAPPED)) {
-                   while ((nlpos[-1] & CHAR_MASK) == 0x20 && nlpos > q)
-                       nlpos--;
-                   if (nlpos < selend)
-                       nl = TRUE;
-               }
-               while (q < nlpos && q < selend)
-                   *p++ = (unsigned char) (*q++ & CHAR_MASK);
-               if (nl) {
-                   int i;
-                   for (i=0; i<sizeof(sel_nl); i++)
-                       *p++ = sel_nl[i];
-               }
-               q = lineend + 1;       /* start of next line */
-           }
-           write_clip (selspace, p - selspace);
+           clipme(selstart, selend);
            selstate = SELECTED;
        } else
            selstate = NO_SELECTION;
-    } else if (b == MB_PASTE && (a==MA_CLICK || a==MA_2CLK || a==MA_3CLK)) {
-       char *data;
-       int len;
-
-       get_clip((void **) &data, &len);
-       if (data) {
-           char *p, *q;
-           p = q = data;
-           while (p < data+len) {
-               while (p < data+len &&
-                      !(p <= data+len-sizeof(sel_nl) &&
-                        !memcmp(p, sel_nl, sizeof(sel_nl))))
-                   p++;
+    } else if (b == MBT_PASTE
+              && (a == MA_CLICK || a == MA_2CLK || a == MA_3CLK)) {
+        term_do_paste();
+    }
 
-               {
-                   int i;
-                   unsigned char c;
-                   for(i=0;i<p-q;i++)
-                   {
-                       c=xlat_kbd2tty(q[i]);
-                       ldisc->send(&c,1);
-                   }
-               }
+    term_update();
+}
 
-               if (p <= data+len-sizeof(sel_nl) &&
-                   !memcmp(p, sel_nl, sizeof(sel_nl))) {
-                   ldisc->send ("\r", 1);
-                   p += sizeof(sel_nl);
-               }
-               q = p;
-           }
-       }
-       get_clip(NULL, NULL);
+void term_nopaste()
+{
+    if (paste_len == 0)
+       return;
+    sfree(paste_buffer);
+    paste_buffer = 0;
+    paste_len = 0;
+}
+
+void term_paste()
+{
+    static long last_paste = 0;
+    long now, paste_diff;
+
+    if (paste_len == 0)
+       return;
+
+    /* Don't wait forever to paste */
+    if (paste_hold) {
+       now = GetTickCount();
+       paste_diff = now - last_paste;
+       if (paste_diff >= 0 && paste_diff < 450)
+           return;
     }
+    paste_hold = 0;
 
-    term_update();
+    while (paste_pos < paste_len) {
+       int n = 0;
+       while (n + paste_pos < paste_len) {
+           if (paste_buffer[paste_pos + n++] == '\r')
+               break;
+       }
+       luni_send(paste_buffer + paste_pos, n);
+       paste_pos += n;
+
+       if (paste_pos < paste_len) {
+           paste_hold = 1;
+           return;
+       }
+    }
+    sfree(paste_buffer);
+    paste_buffer = 0;
+    paste_len = 0;
 }
 
-static void deselect (void) {
+static void deselect(void)
+{
     selstate = NO_SELECTION;
-    selstart = selend = scrtop;
+    selstart.x = selstart.y = selend.x = selend.y = 0;
 }
 
-void term_deselect (void) {
+void term_deselect(void)
+{
     deselect();
     term_update();
 }
+
+int term_ldisc(int option)
+{
+    if (option == LD_ECHO)
+       return term_echoing;
+    if (option == LD_EDIT)
+       return term_editing;
+    return FALSE;
+}
+
+/*
+ * from_backend(), to get data from the backend for the terminal.
+ */
+int from_backend(int is_stderr, char *data, int len)
+{
+    while (len--) {
+       if (inbuf_head >= INBUF_SIZE)
+           term_out();
+       inbuf[inbuf_head++] = *data++;
+    }
+
+    /*
+     * We process all stdout/stderr data immediately we receive it,
+     * and don't return until it's all gone. Therefore, there's no
+     * reason at all to return anything other than zero from this
+     * function.
+     * 
+     * This is a slightly suboptimal way to deal with SSH2 - in
+     * principle, the window mechanism would allow us to continue
+     * to accept data on forwarded ports and X connections even
+     * while the terminal processing was going slowly - but we
+     * can't do the 100% right thing without moving the terminal
+     * processing into a separate thread, and that might hurt
+     * portability. So we manage stdout buffering the old SSH1 way:
+     * if the terminal processing goes slowly, the whole SSH
+     * connection stops accepting data until it's ready.
+     * 
+     * In practice, I can't imagine this causing serious trouble.
+     */
+    return 0;
+}
+
+/*
+ * Log session traffic.
+ */
+void logtraffic(unsigned char c, int logmode)
+{
+    if (cfg.logtype > 0) {
+       if (cfg.logtype == logmode) {
+           /* deferred open file from pgm start? */
+           if (!lgfp)
+               logfopen();
+           if (lgfp)
+               fputc(c, lgfp);
+       }
+    }
+}
+
+/* open log file append/overwrite mode */
+void logfopen(void)
+{
+    char buf[256];
+    time_t t;
+    struct tm *tm;
+    char writemod[4];
+
+    if (!cfg.logtype)
+       return;
+    sprintf(writemod, "wb");          /* default to rewrite */
+    lgfp = fopen(cfg.logfilename, "r");        /* file already present? */
+    if (lgfp) {
+       int i;
+       fclose(lgfp);
+       i = askappend(cfg.logfilename);
+       if (i == 1)
+           writemod[0] = 'a';         /* set append mode */
+       else if (i == 0) {             /* cancelled */
+           lgfp = NULL;
+           cfg.logtype = 0;           /* disable logging */
+           return;
+       }
+    }
+
+    lgfp = fopen(cfg.logfilename, writemod);
+    if (lgfp) {                               /* enter into event log */
+       sprintf(buf, "%s session log (%s mode) to file : ",
+               (writemod[0] == 'a') ? "Appending" : "Writing new",
+               (cfg.logtype == LGTYP_ASCII ? "ASCII" :
+                cfg.logtype == LGTYP_DEBUG ? "raw" : "<ukwn>"));
+       /* Make sure we do not exceed the output buffer size */
+       strncat(buf, cfg.logfilename, 128);
+       buf[strlen(buf)] = '\0';
+       logevent(buf);
+
+       /* --- write header line iinto log file */
+       fputs("=~=~=~=~=~=~=~=~=~=~=~= PuTTY log ", lgfp);
+       time(&t);
+       tm = localtime(&t);
+       strftime(buf, 24, "%Y.%m.%d %H:%M:%S", tm);
+       fputs(buf, lgfp);
+       fputs(" =~=~=~=~=~=~=~=~=~=~=~=\r\n", lgfp);
+    }
+}
+
+void logfclose(void)
+{
+    if (lgfp) {
+       fclose(lgfp);
+       lgfp = NULL;
+    }
+}