diff --git a/src/bbtsub.c b/src/bbtsub.c
index 715ae9d..93f65dc 100644
--- a/src/bbtsub.c
+++ b/src/bbtsub.c
@@ -99,7 +99,7 @@ extern int MonoOrColor;
 /*  take care of cursor movement & hiding  */
 /*  (during bitblts to screen) ourselves.  */
 /*******************************************/
-#if defined(SUNDISPLAY) || defined(DOS)
+#if defined(SUNDISPLAY)
 #define REALCURSOR
 #else
 #undef REALCURSOR
diff --git a/src/bitblt.c b/src/bitblt.c
index 7a52023..394479d 100644
--- a/src/bitblt.c
+++ b/src/bitblt.c
@@ -66,7 +66,7 @@ LispPTR N_OP_pilotbitblt(LispPTR pilot_bt_tbl,int tos)
 {
   PILOTBBT *pbt;
   DLword *srcbase, *dstbase;
-#if defined(SUNDISPLAY) || defined(DOS)
+#if defined(SUNDISPLAY)
   int displayflg;
 #endif
   int sx, dx, w, h, srcbpl, dstbpl, backwardflg;
@@ -100,7 +100,7 @@ LispPTR N_OP_pilotbitblt(LispPTR pilot_bt_tbl,int tos)
 /* if displayflg != 0 then source or destination is DisplayBitMap */
   ScreenLocked = T;
 
-#if SUNDISPLAY || DOS
+#if SUNDISPLAY
   displayflg = cursorin(pbt->pbtdesthi, (pbt->pbtdestlo + (dx >> 4)), w, h, backwardflg) ||
                cursorin(pbt->pbtsourcehi, (pbt->pbtsourcelo + (sx >> 4)), w, h, backwardflg);
 #endif /* SUNDISPLAY */
@@ -118,7 +118,7 @@ LispPTR N_OP_pilotbitblt(LispPTR pilot_bt_tbl,int tos)
 
 #ifdef SUNDISPLAY
   if (displayflg) HideCursor;
-#endif /* SUNDISPLAY / DOS */
+#endif /* SUNDISPLAY */
 
   new_bitblt_code
 
@@ -131,7 +131,7 @@ LispPTR N_OP_pilotbitblt(LispPTR pilot_bt_tbl,int tos)
           if (in_display_segment(dstbase)) flush_display_lineregion(dx, dstbase, w, h);
 #endif
   if (displayflg) ShowCursor;
-#endif /* SUNDISPLAY / DOS */
+#endif /* SUNDISPLAY */
 
 #ifdef XWINDOW
   flush_display_lineregion(dx, dstbase, w, h);
diff --git a/src/dsk.c b/src/dsk.c
index 66cc12d..e027041 100644
--- a/src/dsk.c
+++ b/src/dsk.c
@@ -2493,8 +2493,7 @@ static int make_directory(register char *dir)
 /*	Read thru DIR and gather all files that match FILE into		*/
 /*	VARRAY.  DIR's case must match existing directory's, but	*/
 /*	FILE name matching is case-insensitive.  For UNIX, the 		*/
-/*	versionless file is marked with a version# of 0; for DOS,	*/
-/*	version 0 is the back-up copy of the file.			*/
+/*	versionless file is marked with a version# of 0			*/
 /*									*/
 /************************************************************************/
 
diff --git a/src/dspif.c b/src/dspif.c
index 6294b0f..1e73a8a 100644
--- a/src/dspif.c
+++ b/src/dspif.c
@@ -40,7 +40,7 @@ void make_dsp_instance(DspInterface dsp, char *lispbitmap, int width_hint, int h
     fprintf(stderr, "Can't open display.");
     exit(-1);
   }
-#endif /* DOS | XWINDOW */
+#endif /* XWINDOW */
 } /* Now we know the maximum capabilities of the hardware. */
 
 /*********************************************************************/
diff --git a/src/ether.c b/src/ether.c
index 849592e..a3e452f 100644
--- a/src/ether.c
+++ b/src/ether.c
@@ -58,7 +58,7 @@
 #include <sys/mbuf.h>
 #endif
 #include <nlist.h>
-#endif /* DOS */
+#endif
 
 #include "commondefs.h"
 #include "lispemul.h"
diff --git a/src/initdsp.c b/src/initdsp.c
index f852886..e0b20eb 100644
--- a/src/initdsp.c
+++ b/src/initdsp.c
@@ -60,11 +60,12 @@
 #include "xcursordefs.h"
 #endif
 
-#if defined(XWINDOW) || defined(DOS)
+#if defined(XWINDOW)
 #include "devif.h"
 DLword *DisplayRegion68k_end_addr;
 extern DspInterface currentdsp;
-#endif /* DOS */
+int DisplayWidth8;
+#endif /* XWINDOW */
 
 /* from /usr/include/sun/fbio.h some machines don't have following def. */
 #ifndef FBTYPE_SUNROP_COLOR
@@ -329,7 +330,7 @@ void init_display2(DLword *display_addr, int display_max)
   displayheight = my_screen.fb_height;
 #endif /* SUNDISPLAY */
 
-#if (defined(XWINDOW) || defined(DOS))
+#if defined(XWINDOW)
   (currentdsp->device.enter)(currentdsp);
   displaywidth = currentdsp->Display.width;
   displayheight = currentdsp->Display.height;
@@ -576,12 +577,12 @@ void display_before_exit() {
 
 #endif /* SUNDISPLAY */
 
-#if defined(XWINDOW) || defined(DOS)
+#if defined(XWINDOW)
   (currentdsp->device.exit)(currentdsp);
-#endif /* DOS */
+#endif /* XWINDOW */
 }
 
-#if defined(DISPLAYBUFFER) || defined(DOS)
+#if defined(DISPLAYBUFFER)
 /************************************************************************/
 /*									*/
 /*		    i n _ d i s p l a y _ s e g m e n t			*/
@@ -623,7 +624,7 @@ void flush_display_buffer() {
   (currentdsp->bitblt_to_screen)(currentdsp, DisplayRegion68k, currentdsp->Visible.x,
                                  currentdsp->Visible.y, currentdsp->Visible.width,
                                  currentdsp->Visible.height);
-#endif /* DOS */
+#endif /* XWINDOW */
 }
 
 /************************************************************************/
@@ -652,11 +653,11 @@ void flush_display_region(int x, int y, int w, int h)
 
 #endif /* SUNDISPLAY */
 
-#if (defined(XWINDOW) || defined(DOS))
+#if defined(XWINDOW)
   TPRINT(("Enter flush_display_region x=%d, y=%d, w=%d, h=%d\n", x, y, w, h));
   (currentdsp->bitblt_to_screen)(currentdsp, DisplayRegion68k, x, y, w, h);
   TPRINT(("Exit flush_display_region\n"));
-#endif /* DOS */
+#endif /* XWINDOW */
 }
 #ifdef BYTESWAP
 void byte_swapped_displayregion(int x, int y, int w, int h)
@@ -702,11 +703,11 @@ void flush_display_lineregion(UNSIGNED x, DLword *ybase, UNSIGNED w, UNSIGNED h)
 
 #endif /* SUNDISPLAY */
 
-#if (defined(XWINDOW) || defined(DOS))
+#if defined(XWINDOW)
   TPRINT(("Enter flush_display_lineregion x=%d, y=%d, w=%d, h=%d\n", x, y, w, h));
   (currentdsp->bitblt_to_screen)(currentdsp, DisplayRegion68k, x, y, w, h);
   TPRINT(("Exit flush_display_lineregion\n"));
-#endif /* DOS */
+#endif /* XWINDOW */
 }
 
 /************************************************************************/
@@ -735,9 +736,9 @@ void flush_display_ptrregion(DLword *ybase, UNSIGNED bitoffset, UNSIGNED w, UNSI
 
 #if (defined(SUNDISPLAY) && defined(DISPLAYBUFFER))
   pr_rop(ColorDisplayPixrect, x, y, w, h, COPY_PIXRECT_TO_COLOR, DisplayRegionPixrect, x, y);
-#elif (defined(XWINDOW) || defined(DOS))
+#elif defined(XWINDOW)
   TPRINT(("Enter flush_display_ptrregion\n x=%d, y=%d, w=%d, h=%d\n", x, y, w, h));
   (currentdsp->bitblt_to_screen)(currentdsp, DisplayRegion68k, x, y, w, h);
   TPRINT(("Exit flush_display_ptrregion\n"));
-#endif /* DOS */
+#endif /* SUNDISPLAY & DISPLAYBUFFER, XWINDOW */
 }
diff --git a/src/initkbd.c b/src/initkbd.c
index 98f3999..2af77f9 100644
--- a/src/initkbd.c
+++ b/src/initkbd.c
@@ -226,7 +226,7 @@ void init_keyboard(int flg) /* if 0 init else re-init */
 #elif XWINDOW
   init_Xevent(currentdsp);
 
-#endif /* XWINDOW DOS */
+#endif /* SUNDISPLAY, XWINDOW */
 }
 
 /*  ----------------------------------------------------------------*/
@@ -247,7 +247,7 @@ void device_before_exit() {
   }
   close(LispKbdFd);
 
-#endif /* SUNDISPLAY DOS*/
+#endif /* SUNDISPLAY */
   display_before_exit();
 }
 
@@ -307,7 +307,7 @@ void seteventmask(struct inputmask *eventmask)
 #define KB_DEC3100 (9 + MIN_KEYTYPE) /* TODO: Can we remove this? */
 #define KB_HP9000 (10 + MIN_KEYTYPE)  /* TODO: Can we remove this? */
 #define KB_X (11 + MIN_KEYTYPE)
-#define KB_DOS (12 + MIN_KEYTYPE)
+#define KB_DOS (12 + MIN_KEYTYPE) /* TODO: Can we remove this? */
 
 /* KB_SUN4 not defined in older OS versions */
 #ifndef KB_SUN4
diff --git a/src/kbdsubrs.c b/src/kbdsubrs.c
index aabe035..ca93919 100644
--- a/src/kbdsubrs.c
+++ b/src/kbdsubrs.c
@@ -36,7 +36,7 @@
 #include "devif.h"
 extern KbdInterface currentkbd;
 extern DspInterface currentdsp;
-#endif /* DOS */
+#endif /* XWINDOW */
 
 /****************************************************
  *
@@ -66,13 +66,13 @@ void KB_enable(LispPTR *args) /* args[0] :	ON/OFF flag
     FD_SET(LispWindowFd, &LispReadFds);
 #elif XWINDOW
     enable_Xkeyboard(currentdsp);
-#endif /* DOS */
+#endif /* SUNDISPLAY, XWINDOW */
   } else if (args[0] == NIL) {
 #ifdef SUNDISPLAY
     FD_CLR(LispWindowFd, &LispReadFds);
 #elif XWINDOW
     disable_Xkeyboard(currentdsp);
-#endif /* DOS */
+#endif /* SUNDISPLAY, XWINDOW */
   } else {
     error("KB_enable: illegal arg \n");
     printf("KB_enable: arg = %d\n", args[0]);
@@ -121,7 +121,7 @@ void KB_beep(LispPTR *args) /* args[0] :	ON/OFF flag
 
 #elif XWINDOW
   if (args[0] == ATOM_T) beep_Xkeyboard(currentdsp);
-#endif /* SUNDISPLAY, XWINDOW, DOS */
+#endif /* SUNDISPLAY, XWINDOW */
 }
 
 /****************************************************
diff --git a/src/keyevent.c b/src/keyevent.c
index fe59c0a..c47c11b 100644
--- a/src/keyevent.c
+++ b/src/keyevent.c
@@ -30,7 +30,7 @@
 #include <suntool/window.h>
 #include <ctype.h>
 #include <sundev/kbio.h>
-#endif /* DOS */
+#endif /* SUNDISPLAY */
 
 #include "lispemul.h"
 #include "lspglob.h"
@@ -57,11 +57,11 @@
 #endif /* MAIKO_ENABLE_ETHERNET */
 
 #include "dbprint.h"
-#if (defined(DOS) || defined(XWINDOW))
+#if defined(XWINDOW)
 #include "devif.h"
 extern DspInterface currentdsp;
 extern IOPAGE *IOPage68K;
-#endif /* DOS */
+#endif /* XWINDOW */
 
 /* for contextsw */
 #define AS_OPCODE 1
diff --git a/src/ldsout.c b/src/ldsout.c
index d0c5c75..697387d 100644
--- a/src/ldsout.c
+++ b/src/ldsout.c
@@ -50,10 +50,10 @@ int Storage_expanded; /*  T or NIL */
 /*      Load the sysout file into memory.                               */
 /*                                                                      */
 /************************************************************************/
-#if defined(DOS) || defined(XWINDOW)
+#if defined(XWINDOW)
 #include "devif.h"
 extern DspInterface currentdsp;
-#endif /* DOS || XWINDOW */
+#endif /* XWINDOW */
 
 /* sys_size is sysout size in megabytes */
 int sysout_loader(const char *sysout_file_name, int sys_size) {
@@ -299,11 +299,11 @@ int sysout_loader(const char *sysout_file_name, int sys_size) {
   free(fptovp);
   DBPRINT(("sysout file is read completely.\n"));
 
-#if (defined(DISPLAYBUFFER) || defined(XWINDOW) || defined(DOS))
+#if defined(DISPLAYBUFFER) || defined(XWINDOW)
   TPRINT(("Flushing display buffer...\n"));
   flush_display_buffer();
   TPRINT(("After Flushing display buffer\n"));
-#endif /* DISPLAYBUFFER || XWINDOW || DOS */
+#endif /* DISPLAYBUFFER || XWINDOW */
 
   close(sysout);
   return (sys_size);
diff --git a/src/main.c b/src/main.c
index 51cb661..659892b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -242,10 +242,10 @@ int sysout_size = 0;    /* ditto */
 
 int flushing = FALSE; /* see dbprint.h if set, all debug/trace printing will call fflush(stdout) after each printf */
 
-#if defined(DOS) || defined(XWINDOW)
+#if defined(XWINDOW)
 #include "devif.h"
 extern DspInterface currentdsp;
-#endif /* DOS || XWINDOW */
+#endif /* XWINDOW */
 
 extern time_t MDate;
 extern int nokbdflag;
@@ -261,14 +261,14 @@ const char *helpstring =
  -bw <pixels>             The Medley screen borderwidth\n\
  -g[eometry] <geom>]      The Medley screen geometry\n\
  -sc[reen] <w>x<h>]       The Medley screen geometry\n";
-#else  /* not DOS, not XWINDOW */
+#else  /* not XWINDOW */
 const char *helpstring =
     "\n\
  either setenv LDESRCESYSOUT or do:\n\
  lde[ether] [sysout-name] [<options>]\n\
  -info        Print general info about the system\n\
  -help        Print this message\n";
-#endif /* DOS */
+#endif /* XWINDOW */
 
 /************************************************************************/
 /*									*/
@@ -427,9 +427,9 @@ int main(int argc, char *argv[])
     if (please_fork) fprintf(stderr, "Failed to find UNIXCOMM file handles; no processes\n");
   }
 
-#if defined(DOS) || defined(XWINDOW)
+#if defined(XWINDOW)
   make_dsp_instance(currentdsp, 0, 0, 0, 1); /* All defaults the first time */
-#endif                                       /* DOS || XWINDOW */
+#endif                                       /* XWINDOW */
 
   /* Load sysout to VM space and returns real sysout_size(not 0) */
   sysout_size = sysout_loader(sysout_name, sysout_size);
diff --git a/src/unixcomm.c b/src/unixcomm.c
index 452cf1e..17f420e 100644
--- a/src/unixcomm.c
+++ b/src/unixcomm.c
@@ -6,8 +6,6 @@ Unix Interface Communications
 
 */
 
-/* Don't compile this at all under DOS. */
-
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE /* Needed for ptsname on glibc systems. */
 #endif
diff --git a/src/uraid.c b/src/uraid.c
index e1d4b58..fcb86d6 100644
--- a/src/uraid.c
+++ b/src/uraid.c
@@ -87,10 +87,10 @@ extern int Win_security_p;
 #include "etherdefs.h"
 #endif
 
-#if defined(DOS) || defined(XWINDOW)
+#if defined(XWINDOW)
 #include "devif.h"
 extern DspInterface currentdsp;
-#endif /* DOS || XWINDOW */
+#endif /* XWINDOW */
 
 #ifdef COLOR
 extern int MonoOrColor;
@@ -126,7 +126,7 @@ x Xaddress [xnum]       Hex-Dump xnum word(16-bits) starting at Xaddress
 @ litatom val           Sets TOPVAL of litatom to Decimal-val
 < Xaddress val          Sets the word(16-bits) at the address to val
 <<Return or Exit>>
-e                       Exit to UNIX / DOS
+e                       Exit to UNIX
 h                       Context switch to HARDRESET
 q                       Returns from URAID with NO-change
 <<Misc>>
@@ -928,10 +928,10 @@ int device_before_raid() {
 
 #endif /* SUNDISPLAY */
 
-#if defined(XWINDOW) || defined(DOS)
+#if defined(XWINDOW)
   (currentdsp->cleardisplay)(currentdsp);
   (currentdsp->device.before_raid)(currentdsp);
-#endif /* XWINDOW || DOS */
+#endif /* XWINDOW */
 
   return (0);
 }
@@ -1045,7 +1045,7 @@ int device_after_raid() {
   (currentdsp->device.after_raid)(currentdsp);
   FD_SET(ConnectionNumber(currentdsp->display_id), &LispReadFds);
   flush_display_buffer();
-#endif /* XWINDOW | DOS */
+#endif /* XWINDOW */
 
   int_unblock();
   *EmKbdAd068K = *EmRealUtilin68K = *EmKbdAd168K = *EmKbdAd268K = *EmKbdAd368K = *EmKbdAd468K =
diff --git a/src/vmemsave.c b/src/vmemsave.c
index c26b37e..16dac78 100644
--- a/src/vmemsave.c
+++ b/src/vmemsave.c
@@ -308,7 +308,7 @@ LispPTR vmem_save(char *sysout_file_name)
     EmCursorBitMap68K= NullCursor;*/
 #endif /* OLD_CURSOR */
 
-#endif /* SUNDISPLAY || DOS */
+#endif /* SUNDISPLAY */
 
   /* set FPTOVP */
   fptovp = FPtoVP + 1;
diff --git a/src/xc.c b/src/xc.c
index fcbca31..01d31cd 100644
--- a/src/xc.c
+++ b/src/xc.c
@@ -102,7 +102,7 @@ register InstPtr pccache asm("si");
 register LispPTR *cspcache asm("di");
 register LispPTR tscache asm("bx");
 #include "inlnPS2.h"
-#endif /* DOS */
+#endif /* GCC386 */
 
 /* This used to be here for including optimized dispatch
  * for SPARC, but it has some other things in it, so we