diff --git a/display/display.c b/display/display.c
index 23be9f4..01c1b4d 100644
--- a/display/display.c
+++ b/display/display.c
@@ -259,7 +259,15 @@ static struct display displays[] = {
      * P31 phosphor according to "Heads-Up Display for Flight
      * Simulator for Advanced Aircraft"
      */
-    { DIS_IMLAC, "Imlac Display", &color_p31, NULL, 1024, 1024 }
+    { DIS_IMLAC, "Imlac Display", &color_p31, NULL, 1024, 1024 },
+
+    /*
+     * TT2500 display
+     * 512x512 addressable points.
+     * P31 phosphor according to "Heads-Up Display for Flight
+     * Simulator for Advanced Aircraft"
+     */
+    { DIS_TT2500, "TT2500 Display", &color_p31, NULL, 512, 512 }
 };
 
 /*
diff --git a/display/display.h b/display/display.h
index b680f64..94fb3a4 100644
--- a/display/display.h
+++ b/display/display.h
@@ -51,6 +51,7 @@ enum display_type {
     DIS_III = 111,
     DIS_TYPE340 = 340,
     DIS_NG = 999,
+    DIS_TT2500 = 2500,
 };
 
 /*
diff --git a/display/tt2500.c b/display/tt2500.c
new file mode 100644
index 0000000..6faadb6
--- /dev/null
+++ b/display/tt2500.c
@@ -0,0 +1,115 @@
+/* tt2500.c: TT2500 display interface.
+
+   Copyright (c) 2020, Lars Brinkhoff
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+   LARS BRINKHOFF BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+   Except as contained in this notice, the name of Lars Brinkhoff shall not be
+   used in advertising or otherwise to promote the sale, use or other dealings
+   in this Software without prior written authorization from Lars Brinkhoff
+
+*/
+
+#include "display.h"
+#include "tt2500.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+int tt2500_init(void *dev, int debug)
+{
+  return display_init (DIS_TT2500, 1, dev);
+}
+
+static void tt2500_point (int x, int y, int i)
+{
+  if (i < 7)
+    display_point (x, y, DISPLAY_INT_MAX*(7-i)/7, 0);
+}
+
+int tt2500_cycle(int us, int slowdown)
+{
+  return display_age (us, slowdown);
+}
+
+#define ABS(_X) ((_X) >= 0 ? (_X) : -(_X))
+#define SIGN(_X) ((_X) >= 0 ? 1 : -1)
+
+static void
+xline (int x, int y, int x2, int dx, int dy, int i)
+{
+  int ix = SIGN(dx);
+  int iy = SIGN(dy);
+  int ay;
+
+  dx = ABS(dx);
+  dy = ABS(dy);
+
+  ay = dy/2;
+  for (;;) {
+    tt2500_point (x, y, i);
+    if (x == x2)
+      break;
+    if (ay > 0) {
+      y += iy;
+      ay -= dx;
+    }
+    ay += dy;
+    x += ix;
+  }
+}
+  
+static void
+yline (int x, int y, int y2, int dx, int dy, int i)
+{
+  int ix = SIGN(dx);
+  int iy = SIGN(dy);
+  int ax;
+
+  dx = ABS(dx);
+  dy = ABS(dy);
+
+  ax = dx/2;
+  for (;;) {
+    tt2500_point (x, y, i);
+    if (y == y2)
+      break;
+    if (ax > 0) {
+      x += ix;
+      ax -= dy;
+    }
+    ax += dx;
+    y += iy;
+  }
+}
+
+void
+tt2500_line (int x1, int y1, int x2, int y2, int i)
+{
+  int dx = x2 - x1;
+  int dy = y2 - y1;
+  if (ABS (dx) > ABS(dy))
+    xline (x1, y1, x2, dx, dy, i);
+  else
+    yline (x1, y1, y2, dx, dy, i);
+}
+
+#if defined(__cplusplus)
+}
+#endif
diff --git a/display/tt2500.h b/display/tt2500.h
new file mode 100644
index 0000000..f422a0b
--- /dev/null
+++ b/display/tt2500.h
@@ -0,0 +1,37 @@
+/* tt2500.h: TT2500 display interface.
+
+   Copyright (c) 2020, Lars Brinkhoff.
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+   LARS BRINKHOFF BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+   Except as contained in this notice, the name of Lars Brinkhoff shall not be
+   used in advertising or otherwise to promote the sale, use or other dealings
+   in this Software without prior written authorization from Lars Brinkhoff
+*/
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+extern int tt2500_init(void *, int);
+extern int tt2500_cycle(int, int);
+extern void tt2500_line(int x1, int y1, int x2, int y2, int i);
+
+#if defined(__cplusplus)
+}
+#endif