fix tools for openwatcom

tools.c

@@ -7,19 +7,35 @@
 
 int key_pressed(void)
 {
+#ifdef __WATCOMC__
+  /*
+   * Open Watcom's WORDREGS does not expose x.flags.  The old Borland
+   * code checked the BIOS INT 16h ZF bit after AH=01h.  Open Watcom's
+   * bios.h provides _bios_keybrd(), which wraps the same BIOS keyboard
+   * service and returns 0 when no key is waiting.
+   */
+  return(_bios_keybrd(_KEYBRD_READY) != 0);
+#else
   REGS regsin, regsout;
   regsin.h.ah = 0x01; /* read key-press */
   int86(0x16, &regsin, &regsout);
   return((regsout.x.flags & 0x40) ? 0 : 1); /* zeroflag != 0 */
+#endif
 }
 
 void clear_kb(void)
 {
+#ifdef __WATCOMC__
+  while (key_pressed()) {
+    (void)_bios_keybrd(_KEYBRD_READ);
+  }
+#else
   REGS regsin, regsout;
   while (key_pressed()) {    /* zeroflag != 0 */
     regsin.h.ah = 0x00;      /* read key-press */
     int86(0x16, &regsin, &regsout);
   }
+#endif
 }
 
 int ask_user(char *p, ...)