12 files changed, 137 insertions, 106 deletions

diff --git a/etc/TODO b/etc/TODO
index 81e04fd7948..f13869a05f1 100644
--- a/etc/TODO
+++ b/etc/TODO
@@ -137,7 +137,10 @@ Other features we would like:
 * Highlight rectangles (`mouse-track-rectangle-p' in XEmacs).  Already in CUA,
   but it's a valuable feature worth making more general.
 
-* Support simultaneous tty and X frames.
+* Support simultaneous tty and X frames.  [For a partial
+  implementation, see tla branch
+  lorentey@elte.hu--2004/emacs--multi-tty--0 at
+  http://lorentey.web.elte.hu/arch/2004]
 
 * Provide MIME support for Rmail using the Gnus MIME library.  [Maybe
   not now feasible, given Gnus maintenance decisions.  fx looked at
diff --git a/src/dispnew.c b/src/dispnew.c
index 279c1f10e58..9eb69ebf79d 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -1397,7 +1397,7 @@ line_hash_code (row)
         {
           int c = glyph->u.ch;
           int face_id = glyph->face_id;
-          if (must_write_spaces)
+          if (TERMINAL_MUST_WRITE_SPACES (CURRENT_TERMINAL ()))
             c -= SPACEGLYPH;
           hash = (((hash << 4) + (hash >> 24)) & 0x0fffffff) + c;
           hash = (((hash << 4) + (hash >> 24)) & 0x0fffffff) + face_id;
@@ -1429,7 +1429,7 @@ line_draw_cost (matrix, vpos)
   int glyph_table_len = GLYPH_TABLE_LENGTH;
 
   /* Ignore trailing and leading spaces if we can.  */
-  if (!must_write_spaces)
+  if (!TERMINAL_MUST_WRITE_SPACES (CURRENT_TERMINAL ()))
     {
       /* Skip from the end over trailing spaces.  */
       while (end > beg && CHAR_GLYPH_SPACE_P (*(end - 1)))
@@ -3462,7 +3462,7 @@ direct_output_for_insert (g)
 
   /* If we can't insert glyphs, we can use this method only
      at the end of a line.  */
-  if (!char_ins_del_ok)
+  if (!TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()))
     if (PT != ZV && FETCH_BYTE (PT_BYTE) != '\n')
       return 0;
 
@@ -5075,7 +5075,7 @@ update_frame_1 (f, force_p, inhibit_id_p)
     }
 
   /* If we cannot insert/delete lines, it's no use trying it.  */
-  if (!line_ins_del_ok)
+  if (!TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()))
     inhibit_id_p = 1;
 
   /* See if any of the desired lines are enabled; don't compute for
@@ -5293,21 +5293,23 @@ scrolling (frame)
     }
 
   /* If changed lines are few, don't allow preemption, don't scroll.  */
-  if ((!scroll_region_ok && changed_lines < baud_rate / 2400)
+  if ((!TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
+       && changed_lines < baud_rate / 2400)
       || unchanged_at_bottom == FRAME_LINES (frame))
     return 1;
 
   window_size = (FRAME_LINES (frame) - unchanged_at_top
                  - unchanged_at_bottom);
 
-  if (scroll_region_ok)
+  if (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
     free_at_end_vpos -= unchanged_at_bottom;
-  else if (memory_below_frame)
+  else if (TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()))
     free_at_end_vpos = -1;
 
   /* If large window, fast terminal and few lines in common between
      current frame and desired frame, don't bother with i/d calc.  */
-  if (!scroll_region_ok && window_size >= 18 && baud_rate > 2400
+  if (!TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
+      && window_size >= 18 && baud_rate > 2400
       && (window_size >=
           10 * scrolling_max_lines_saved (unchanged_at_top,
                                           FRAME_LINES (frame) - unchanged_at_bottom,
@@ -5387,7 +5389,7 @@ update_frame_line (f, vpos)
   struct glyph_row *current_row = MATRIX_ROW (current_matrix, vpos);
   struct glyph_row *desired_row = MATRIX_ROW (desired_matrix, vpos);
   int must_write_whole_line_p;
-  int write_spaces_p = must_write_spaces;
+  int write_spaces_p = TERMINAL_MUST_WRITE_SPACES (CURRENT_TERMINAL ());
   int colored_spaces_p = (FACE_FROM_ID (f, DEFAULT_FACE_ID)->background
                           != FACE_TTY_DEFAULT_BG_COLOR);
 
@@ -5466,7 +5468,7 @@ update_frame_line (f, vpos)
       nlen--;
 
   /* If there's no i/d char, quickly do the best we can without it.  */
-  if (!char_ins_del_ok)
+  if (!TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()))
     {
       int i, j;
 
@@ -5569,7 +5571,8 @@ update_frame_line (f, vpos)
 
   tem = (nlen - nsp) - (olen - osp);
   if (endmatch && tem
-      && (!char_ins_del_ok || endmatch <= char_ins_del_cost (f)[tem]))
+      && (!TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ())
+          || endmatch <= char_ins_del_cost (f)[tem]))
     endmatch = 0;
 
   /* nsp - osp is the distance to insert or delete.
@@ -5578,7 +5581,7 @@ update_frame_line (f, vpos)
      Is it worth it?  */
 
   if (nsp != osp
-      && (!char_ins_del_ok
+      && (!TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ())
           || begmatch + endmatch <= char_ins_del_cost (f)[nsp - osp]))
     {
       begmatch = 0;
diff --git a/src/macterm.c b/src/macterm.c
index f0f5a3f4722..7d27e5430eb 100644
--- a/src/macterm.c
+++ b/src/macterm.c
@@ -8674,12 +8674,13 @@ mac_initialize ()
   redeem_scroll_bar_hook = XTredeem_scroll_bar;
   judge_scroll_bars_hook = XTjudge_scroll_bars;
 
-  scroll_region_ok = 1;         /* we'll scroll partial frames */
-  char_ins_del_ok = 1;
-  line_ins_del_ok = 1;          /* we'll just blt 'em */
-  fast_clear_end_of_line = 1;   /* X does this well */
-  memory_below_frame = 0;       /* we don't remember what scrolls
-                                   off the bottom */
+  TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()) = 1; /* we'll scroll partial frames */
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 1;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()) = 1; /* we'll just blt 'em */
+  TERMINAL_FAST_CLEAR_END_OF_LINE (CURRENT_TERMINAL ()) = 1; /* X does this well */
+  TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()) = 0; /* we don't remember what
+                                                         scrolls off the
+                                                         bottom */
   baud_rate = 19200;
 
   x_noop_count = 0;
diff --git a/src/msdos.c b/src/msdos.c
index a2fd011e74c..103094141bf 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -2580,7 +2580,7 @@ internal_terminal_init ()
   set_terminal_modes_hook = IT_set_terminal_modes;
   reset_terminal_modes_hook = IT_reset_terminal_modes;
   set_terminal_window_hook = IT_set_terminal_window;
-  char_ins_del_ok = 0;
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 0;
 #endif
 }
 
diff --git a/src/scroll.c b/src/scroll.c
index 6c6aa4abf98..a786d3c2cf4 100644
--- a/src/scroll.c
+++ b/src/scroll.c
@@ -100,7 +100,8 @@ calculate_scrolling (frame, matrix, window_size, lines_below,
   register struct matrix_elt *p, *p1;
   register int cost, cost1;
 
-  int lines_moved = window_size + (scroll_region_ok ? 0 : lines_below);
+  int lines_moved = window_size
+    + (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()) ? 0 : lines_below);
   /* first_insert_cost[I] is the cost of doing the first insert-line
      at the i'th line of the lines we are considering,
      where I is origin 1 (as it is below).  */
@@ -466,7 +467,8 @@ calculate_direct_scrolling (frame, matrix, window_size, lines_below,
   /* Overhead of setting the scroll window, plus the extra cost
      cost of scrolling by a distance of one.  The extra cost is
      added once for consistency with the cost vectors */
-  scroll_overhead = scroll_region_cost + extra_cost;
+  scroll_overhead
+    = TERMINAL_SCROLL_REGION_COST (CURRENT_TERMINAL ()) + extra_cost;
 
   /* initialize the top left corner of the matrix */
   matrix->writecost = 0;
@@ -818,7 +820,7 @@ scrolling_1 (frame, window_size, unchanged_at_top, unchanged_at_bottom,
   matrix = ((struct matrix_elt *)
             alloca ((window_size + 1) * (window_size + 1) * sizeof *matrix));
 
-  if (scroll_region_ok)
+  if (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
     {
       calculate_direct_scrolling (frame, matrix, window_size,
                                   unchanged_at_bottom,
@@ -914,7 +916,7 @@ scroll_cost (frame, from, to, amount)
   if (amount == 0)
     return 0;
 
-  if (! scroll_region_ok)
+  if (! TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
     limit = height;
   else if (amount > 0)
     limit += amount;
diff --git a/src/sysdep.c b/src/sysdep.c
index 441b36290e1..b83e01635cc 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -5126,7 +5126,8 @@ hft_init ()
   }
   /* The HFT system on AIX doesn't optimize for scrolling, so it's really ugly
      at times.  */
-  line_ins_del_ok = char_ins_del_ok = 0;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()) = 0;
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 0;
 }
 
 /* Reset the rubout key to backspace.  */
diff --git a/src/term.c b/src/term.c
index 5c25c7419dc..50d47a1dac1 100644
--- a/src/term.c
+++ b/src/term.c
@@ -83,28 +83,13 @@ static void tty_hide_cursor P_ ((void));
 
 Lisp_Object Vring_bell_function;
 
-/* Terminal characteristics that higher levels want to look at.
-   These are all extern'd in termchar.h */
-
-int must_write_spaces;          /* Nonzero means spaces in the text
-                                   must actually be output; can't just skip
-                                   over some columns to leave them blank.  */
-int min_padding_speed;          /* Speed below which no padding necessary */
-
-int line_ins_del_ok;            /* Terminal can insert and delete lines */
-int char_ins_del_ok;            /* Terminal can insert and delete chars */
-int scroll_region_ok;           /* Terminal supports setting the
-                                   scroll window */
-int scroll_region_cost;         /* Cost of setting a scroll window,
-                                   measured in characters */
-int memory_below_frame;         /* Terminal remembers lines
-                                   scrolled off bottom */
-int fast_clear_end_of_line;     /* Terminal has a `ce' string */
+/* Terminal characteristics that higher levels want to look at. */
+static struct terminal _current_terminal;
+TERMINAL_PTR current_terminal = &_current_terminal;
 
 /* Nonzero means no need to redraw the entire frame on resuming
    a suspended Emacs.  This is useful on terminals with multiple pages,
    where one page is used for Emacs and another for all else. */
-
 int no_redraw_on_reenter;
 
 /* Hook functions that you can set to snap out the functions in this file.
@@ -505,7 +490,7 @@ set_terminal_window (size)
   if (FRAME_TERMCAP_P (updating_frame))
     {
       specified_window = size ? size : FRAME_LINES (updating_frame);
-      if (scroll_region_ok)
+      if (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
         set_scroll_region (0, specified_window);
     }
   else
@@ -1151,9 +1136,11 @@ ins_del_lines (vpos, n)
   /* If the lines below the deletion are blank lines coming
      out of the end of the window, don't bother,
      as there will be a matching inslines later that will flush them. */
-  if (scroll_region_ok && vpos + i >= specified_window)
+  if (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
+      && vpos + i >= specified_window)
     return;
-  if (!memory_below_frame && vpos + i >= FRAME_LINES (sf))
+  if (!TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ())
+      && vpos + i >= FRAME_LINES (sf))
     return;
 
   if (multi)
@@ -1186,7 +1173,9 @@ ins_del_lines (vpos, n)
       set_scroll_region (0, specified_window);
     }
 
-  if (!scroll_region_ok && memory_below_frame && n < 0)
+  if (!TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
+      && TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ())
+      && n < 0)
     {
       cursor_to (FRAME_LINES (sf) + n, 0);
       clear_to_end ();
@@ -1317,7 +1306,7 @@ calculate_costs (frame)
 
   FRAME_COST_BAUD_RATE (frame) = baud_rate;
 
-  scroll_region_cost = string_cost (f);
+  TERMINAL_SCROLL_REGION_COST (CURRENT_TERMINAL ()) = string_cost (f);
 
   /* These variables are only used for terminal stuff.  They are allocated
      once for the terminal frame of X-windows emacs, but not used afterwards.
@@ -2185,15 +2174,15 @@ term_init (terminal_type)
   delete_in_insert_mode = 1;
 
   UseTabs = 0;
-  scroll_region_ok = 0;
+  TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()) = 0;
 
   /* Seems to insert lines when it's not supposed to, messing
      up the display.  In doing a trace, it didn't seem to be
      called much, so I don't think we're losing anything by
      turning it off.  */
 
-  line_ins_del_ok = 0;
-  char_ins_del_ok = 1;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()) = 0;
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 1;
 
   baud_rate = 19200;
 
@@ -2346,9 +2335,9 @@ to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
   /* Since we make MagicWrap terminals look like AutoWrap, we need to have
      the former flag imply the latter.  */
   AutoWrap = MagicWrap || tgetflag ("am");
-  memory_below_frame = tgetflag ("db");
+  TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()) = tgetflag ("db");
   TF_hazeltine = tgetflag ("hz");
-  must_write_spaces = tgetflag ("in");
+  TERMINAL_MUST_WRITE_SPACES (CURRENT_TERMINAL ()) = tgetflag ("in");
   meta_key = tgetflag ("km") || tgetflag ("MT");
   TF_insmode_motion = tgetflag ("mi");
   TF_standout_motion = tgetflag ("ms");
@@ -2377,7 +2366,10 @@ to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
     fatal ("Screen size %dx%d is too small",
            FRAME_LINES (sf), FRAME_COLS (sf));
 
-  min_padding_speed = tgetnum ("pb");
+#if 0  /* This is not used anywhere. */
+  TERMINAL_MIN_PADDING_SPEED (CURRENT_TERMINAL ()) = tgetnum ("pb");
+#endif
+  
   TabWidth = tgetnum ("tw");
 
 #ifdef VMS
@@ -2453,7 +2445,7 @@ to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
 
   if (!strcmp (terminal_type, "supdup"))
     {
-      memory_below_frame = 1;
+      TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()) = 1;
       Wcm.cm_losewrap = 1;
     }
   if (!strncmp (terminal_type, "c10", 3)
@@ -2480,7 +2472,7 @@ to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
             TS_set_window = "\033v%C %C %C %C ";
         }
       /* Termcap entry often fails to have :in: flag */
-      must_write_spaces = 1;
+      TERMINAL_MUST_WRITE_SPACES (CURRENT_TERMINAL ()) = 1;
       /* :ti string typically fails to have \E^G! in it */
       /* This limits scope of insert-char to one line.  */
       strcpy (area, TS_termcap_modes);
@@ -2543,19 +2535,22 @@ to do `unset TERMCAP' (C-shell: `unsetenv TERMCAP') as well.",
 
   UseTabs = tabs_safe_p () && TabWidth == 8;
 
-  scroll_region_ok
+  TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
     = (Wcm.cm_abs
        && (TS_set_window || TS_set_scroll_region || TS_set_scroll_region_1));
 
-  line_ins_del_ok = (((TS_ins_line || TS_ins_multi_lines)
-                      && (TS_del_line || TS_del_multi_lines))
-                     || (scroll_region_ok && TS_fwd_scroll && TS_rev_scroll));
-
-  char_ins_del_ok = ((TS_ins_char || TS_insert_mode
-                      || TS_pad_inserted_char || TS_ins_multi_chars)
-                     && (TS_del_char || TS_del_multi_chars));
-
-  fast_clear_end_of_line = TS_clr_line != 0;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ())
+    = (((TS_ins_line || TS_ins_multi_lines)
+        && (TS_del_line || TS_del_multi_lines))
+       || (TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ())
+           && TS_fwd_scroll && TS_rev_scroll));
+  
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ())
+    = ((TS_ins_char || TS_insert_mode
+        || TS_pad_inserted_char || TS_ins_multi_chars)
+       && (TS_del_char || TS_del_multi_chars));
+
+  TERMINAL_FAST_CLEAR_END_OF_LINE (CURRENT_TERMINAL ()) = TS_clr_line != 0;
 
   init_baud_rate ();
   if (read_socket_hook)         /* Baudrate is somewhat */
diff --git a/src/termchar.h b/src/termchar.h
index b1d941adc27..b7c82d04936 100644
--- a/src/termchar.h
+++ b/src/termchar.h
@@ -18,32 +18,51 @@ along with GNU Emacs; see the file COPYING.  If not, write to
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+struct terminal
+{
+  
+  /* EMACS_INT baud_rate; */    /* Output speed in baud */
+  int must_write_spaces;        /* Nonzero means spaces in the text must
+                                   actually be output; can't just skip over
+                                   some columns to leave them blank.  */
+  int fast_clear_end_of_line;   /* Nonzero means terminal has a `ce' string */
+  
+  int line_ins_del_ok;          /* Terminal can insert and delete lines */
+  int char_ins_del_ok;          /* Terminal can insert and delete chars */
+  int scroll_region_ok;         /* Terminal supports setting the scroll
+                                   window */
+  int scroll_region_cost;       /* Cost of setting the scroll window,
+                                   measured in characters. */
+  int memory_below_frame;       /* Terminal remembers lines scrolled
+                                   off bottom */
 
-/* extern EMACS_INT baud_rate; */               /* Output speed in baud */
-extern int must_write_spaces;   /* Nonzero means spaces in the text
-                                   must actually be output; can't just skip
-                                   over some columns to leave them blank.  */
-extern int min_padding_speed;   /* Speed below which no padding necessary */
-extern int fast_clear_end_of_line; /* Nonzero means terminal has
-                                      command for this */
-
-extern int line_ins_del_ok;     /* Terminal can insert and delete lines */
-extern int char_ins_del_ok;     /* Terminal can insert and delete chars */
-extern int scroll_region_ok;    /* Terminal supports setting the scroll
-                                   window */
-extern int scroll_region_cost;  /* Cost of setting the scroll window,
-                                   measured in characters */
-extern int memory_below_frame;  /* Terminal remembers lines scrolled
-                                   off bottom */
-extern int fast_clear_end_of_line; /* Terminal has a `ce' string */
-
-extern int dont_calculate_costs; /* Nonzero means don't bother computing
-                                    various cost tables; we won't use them. */
-
-/* Nonzero means no need to redraw the entire frame on resuming
-   a suspended Emacs.  This is useful on terminals with multiple pages,
-   where one page is used for Emacs and another for all else. */
-extern int no_redraw_on_reenter;
+#if 0  /* These are not used anywhere. */
+  int min_padding_speed;        /* Speed below which no padding necessary. */
+  int dont_calculate_costs;     /* Nonzero means don't bother computing
+                                   various cost tables; we won't use them. */
+#endif
+};
+
+typedef struct terminal *TERMINAL_PTR;
+
+extern TERMINAL_PTR current_terminal;
+
+#define CURRENT_TERMINAL() \
+  (current_terminal ? current_terminal : (abort(), (TERMINAL_PTR) 0))
+
+#define TERMINAL_MUST_WRITE_SPACES(t) ((t)->must_write_spaces)
+#define TERMINAL_FAST_CLEAR_END_OF_LINE(t) ((t)->fast_clear_end_of_line)
+#define TERMINAL_LINE_INS_DEL_OK(t) ((t)->line_ins_del_ok)
+#define TERMINAL_CHAR_INS_DEL_OK(t) ((t)->char_ins_del_ok)
+#define TERMINAL_SCROLL_REGION_OK(t) ((t)->scroll_region_ok)
+#define TERMINAL_SCROLL_REGION_COST(t) ((t)->scroll_region_cost)
+#define TERMINAL_MEMORY_BELOW_FRAME(t) ((t)->memory_below_frame)
+
+#if 0
+/* These are not used anywhere. */
+#define TERMINAL_MIN_PADDING_SPEED(t) ((t)->min_padding_speed)
+#define TERMINAL_DONT_CALCULATE_COSTS(t) ((t)->dont_calculate_costs)
+#endif
 
 /* arch-tag: bf9f0d49-842b-42fb-9348-ec8759b27193
    (do not change this comment) */
diff --git a/src/termopts.h b/src/termopts.h
index 2dc798ea2c4..10f0083a667 100644
--- a/src/termopts.h
+++ b/src/termopts.h
@@ -40,5 +40,10 @@ extern int meta_key;
 /* Nonzero means truncate lines in all windows less wide than the frame */
 extern int truncate_partial_width_windows;
 
+/* Nonzero means no need to redraw the entire frame on resuming a suspended
+   Emacs.  This is useful on terminals with multiple pages, where one page is
+   used for Emacs and another for all else. */
+extern int no_redraw_on_reenter;
+
 /* arch-tag: 35d4d284-dc1a-4fff-97fa-0154a21aebdb
    (do not change this comment) */
diff --git a/src/w32term.c b/src/w32term.c
index 3e4543471c3..cf8d07a18ff 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -6366,12 +6366,13 @@ w32_initialize ()
   redeem_scroll_bar_hook = w32_redeem_scroll_bar;
   judge_scroll_bars_hook = w32_judge_scroll_bars;
 
-  scroll_region_ok = 1;         /* we'll scroll partial frames */
-  char_ins_del_ok = 1;
-  line_ins_del_ok = 1;          /* we'll just blt 'em */
-  fast_clear_end_of_line = 1;   /* X does this well */
-  memory_below_frame = 0;       /* we don't remember what scrolls
-                                   off the bottom */
+  TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()) = 1; /* we'll scroll partial frames */
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 1;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()) = 1; /* we'll just blt 'em */
+  TERMINAL_FAST_CLEAR_END_OF_LINE (CURRENT_TERMINAL ()) = 1; /* X does this well */
+  TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()) = 0; /* we don't remember what
+                                                            scrolls off the
+                                                            bottom */
   baud_rate = 19200;
 
   w32_system_caret_hwnd = NULL;
diff --git a/src/xdisp.c b/src/xdisp.c
index c2717552cc5..252c6c824b3 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -12889,7 +12889,7 @@ try_window_id (w)
 
   /* Window must either use window-based redisplay or be full width.  */
   if (!FRAME_WINDOW_P (f)
-      && (!line_ins_del_ok
+      && (!TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ())
           || !WINDOW_FULL_WIDTH_P (w)))
     GIVE_UP (4);
 
@@ -13322,7 +13322,7 @@ try_window_id (w)
 
               /* On dumb terminals delete dvpos lines at the end
                  before inserting dvpos empty lines.  */
-              if (!scroll_region_ok)
+              if (!TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
                 ins_del_lines (end - dvpos, -dvpos);
 
               /* Insert dvpos empty lines in front of
@@ -13343,7 +13343,7 @@ try_window_id (w)
 
               /* On a dumb terminal insert dvpos empty lines at the
                  end.  */
-              if (!scroll_region_ok)
+              if (!TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()))
                 ins_del_lines (end + dvpos, -dvpos);
             }
 
diff --git a/src/xterm.c b/src/xterm.c
index a3117846702..8718d76bc31 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10852,12 +10852,13 @@ x_initialize ()
   redeem_scroll_bar_hook = XTredeem_scroll_bar;
   judge_scroll_bars_hook = XTjudge_scroll_bars;
 
-  scroll_region_ok = 1;         /* we'll scroll partial frames */
-  char_ins_del_ok = 1;
-  line_ins_del_ok = 1;          /* we'll just blt 'em */
-  fast_clear_end_of_line = 1;   /* X does this well */
-  memory_below_frame = 0;       /* we don't remember what scrolls
-                                   off the bottom */
+  TERMINAL_SCROLL_REGION_OK (CURRENT_TERMINAL ()) = 1; /* we'll scroll partial frames */
+  TERMINAL_CHAR_INS_DEL_OK (CURRENT_TERMINAL ()) = 1;
+  TERMINAL_LINE_INS_DEL_OK (CURRENT_TERMINAL ()) = 1; /* we'll just blt 'em */
+  TERMINAL_FAST_CLEAR_END_OF_LINE (CURRENT_TERMINAL ()) = 1; /* X does this well */
+  TERMINAL_MEMORY_BELOW_FRAME (CURRENT_TERMINAL ()) = 0; /* we don't remember what
+                                                         scrolls off the
+                                                         bottom */
   baud_rate = 19200;
 
   x_noop_count = 0;