Date: Mon, 3 Aug 92 02:50:34 -0500
From: rcharif AT math DOT utexas DOT edu
Posted-Date: Mon, 3 Aug 92 02:50:34 -0500
To: dj AT ctron DOT com
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: BUG in paging patch
Reply-To: rcharif AT math DOT utexas DOT edu


I am terribly sorry but I just discovered a bug in the modification
that rendered the current eip skip routine useless. This has been
corrected and a new version of the files is on math.utexas.edu. (See
previous message).

And again sorry for the inconvenience.

Here is the diff again
-------------- CUT HERE ----------------------------

diff -c3 orig/build.h a/build.h
*** orig/build.h	Mon Aug  3 01:15:32 1992
--- a/build.h	Sun Aug  2 20:42:40 1992
***************
*** 13,15 ****
--- 13,30 ----
  */
  
  /* moved to makefile */
+ 
+ #ifdef DEBUG_ON
+ 
+ static char *_pFileName = __FILE__;
+ 
+ extern unsigned long fDebug;
+ #define  DEBUG(n)    if (fDebug & n)
+ 
+ #define  DEBUG_POUT              1
+ #define  DEBUG_PIN               2
+ #define  DEBUG_POUT_DATA_DIRTY   4
+ #define  DEBUG_POUT_DISCARD      8
+ #define  DEBUG_SKIP_EIP         16
+ 
+ #endif
diff -c3 orig/control.c a/control.c
*** orig/control.c	Tue Jul  7 17:29:14 1992
--- a/control.c	Sun Aug  2 23:16:38 1992
***************
*** 38,43 ****
--- 38,47 ----
  extern transfer_buffer[];
  extern word32 transfer_linear;
  
+ #ifdef DEBUG
+ unsigned long fDebug = 0;  // Debug messages mask, see build.h
+ #endif
+ 
  TSS *tss_ptr;
  int debug_mode = 0;
  int self_contained;
***************
*** 186,192 ****
--- 190,200 ----
  
  usage(char *s)
  {
+ #ifdef DEBUG
+   printf("Usage: %s [-debug <flag value>] [program [options . . . ]]\n", s);
+ #else
    printf("Usage: %s [program [options . . . ]]\n", s);
+ #endif
    _exit(1);
  }
  
***************
*** 350,355 ****
--- 358,373 ----
          if (emu_fn) free(emu_fn);
          emu_fn = strdup(val);
        }
+       else if (stricmp(sw, "debug") == 0) {
+ 
+          if (!strcmpi(val, "all"))
+             fDebug = 0xffffffffL;
+          else 
+             sscanf(val, "%li", (unsigned long *)&fDebug);
+ 
+          printf("\nMessage Debugging enabled in go32 environment variable. Flag value = %lx\n"
+             , fDebug);
+          }
      }
  #if ! DEBUGGER
  #if ! TOPLINEINFO
***************
*** 447,452 ****
--- 465,485 ----
      argc--;
    }
  
+ #ifdef DEBUG
+    // set debug flags. syntaxe go32 [-debug <all || debug_flags_value>] pgm_name
+    if (!strncmpi(argv[1], "-debug", 6)) {
+ 
+       if (!strcmpi(argv[2], "all"))
+          fDebug = 0xffffffffL;
+       else 
+          sscanf(argv[2], "%li", (unsigned long *)&fDebug);
+ 
+       argv += 2;
+       argc -= 2;
+       printf("\nMessage Debugging enabled. Flag value = %lx\n", fDebug);
+       }
+ #endif
+ 
  #if TOPLINEINFO
    for (i=0; i<80; i++)
      poke(screen_seg, i*2, 0x0720);
***************
*** 490,496 ****
      *path = 0;
      if (stat(argv0, &stbuf)) /* not found */
      {
!       fprintf(stderr, "%s.exe version 1.07 Copyright (C) 1991 DJ Delorie\n",
                argv0);
        debug_mode = 1;
        if (argv[1] == 0)
--- 523,529 ----
      *path = 0;
      if (stat(argv0, &stbuf)) /* not found */
      {
!       fprintf(stderr, "%s.exe version 1.07 Copyright (C) 1991 DJ Delorie\n\r",
                argv0);
        debug_mode = 1;
        if (argv[1] == 0)
diff -c3 orig/makefile a/makefile
*** orig/makefile	Sat Aug  1 19:58:24 1992
--- a/makefile	Sun Aug  2 18:22:34 1992
***************
*** 1,16 ****
  # History:25,17
  
  AFLAGS = /mx /zi /zd
! CFLAGS = -ms -M
  
  .c.obj:
! 	tcc $(CFLAGS) -DDEBUGGER=1 -DTOPLINEINFO=1 -DSOURCE_LIST -c $*
! 	-mv $*.obj d$*.obj
! 	tcc $(CFLAGS) -DDEBUGGER=0 -DTOPLINEINFO=1 -c $*
  
  .asm.obj:
! 	tasm $(AFLAGS) /DDEBUGGER=1 /DTOPLINEINFO=1 $*;
! 	mv $*.obj d$*.obj
  	tasm $(AFLAGS) /DDEBUGGER=0 /DTOPLINEINFO=1 $*;
  
  OBJS =\
--- 1,16 ----
  # History:25,17
  
  AFLAGS = /mx /zi /zd
! CFLAGS = -ms -M -DVERBOSE=0 -DDEBUG_ON
  
  .c.obj:
! #	bcc $(CFLAGS) -DDEBUGGER=1 -DTOPLINEINFO=1 -DSOURCE_LIST -c $*.c
! #	-mv $*.obj d$*.obj
! 	bcc $(CFLAGS) -DDEBUGGER=0 -DTOPLINEINFO=1 -c $*.c
  
  .asm.obj:
! #	tasm $(AFLAGS) /DDEBUGGER=1 /DTOPLINEINFO=1 $*;
! #	-mv $*.obj d$*.obj
  	tasm $(AFLAGS) /DDEBUGGER=0 /DTOPLINEINFO=1 $*;
  
  OBJS =\
***************
*** 37,43 ****
  	xms.obj\
  	vcpi.obj
  
! all : go32t.exe stub.exe aout2exe.exe exe2aout.exe
  
  stub.exe: stub.c
  	tcc stub.c
--- 37,44 ----
  	xms.obj\
  	vcpi.obj
  
! all : go32.exe
! # stub.exe aout2exe.exe exe2aout.exe
  
  stub.exe: stub.c
  	tcc stub.c
***************
*** 44,52 ****
  	tdstrip stub
  
  # Note: some tlinks require /3 here, some barf if you supply it.
! go32t.exe : $(OBJS) go32.lnk 
  	tlink /3 /l /c /v /s /m @go32.lnk
! 	tlink /3 /l /c /v /s /m @debug32.lnk
  
  bin2byte.exe : bin2byte.c
  	tcc bin2byte.c
--- 45,53 ----
  	tdstrip stub
  
  # Note: some tlinks require /3 here, some barf if you supply it.
! go32.exe : $(OBJS) go32.lnk 
  	tlink /3 /l /c /v /s /m @go32.lnk
! #	tlink /3 /l /c /v /s /m @debug32.lnk
  
  bin2byte.exe : bin2byte.c
  	tcc bin2byte.c
***************
*** 65,91 ****
  
  # DEPENDENCIES
  
! debug.obj : build.h types.h gdt.h tss.h utils.h unassmbl.h syms.h paging.h npx.h mono.h eventque.h
  
! exphdlr.obj : build.h types.h gdt.h idt.h tss.h utils.h paging.h npx.h mono.h vcpi.h eventque.h 
  
! control.obj : build.h types.h gdt.h idt.h tss.h valloc.h utils.h syms.h graphics.h mono.h vcpi.h
  
! graphics.obj : build.h types.h paging.h graphics.h tss.h gdt.h driver.h
  
! paging.obj : build.h types.h paging.h graphics.h tss.h idt.h gdt.h valloc.h dalloc.h utils.h aout.h mono.h vcpi.h
  
! syms.obj : build.h types.h syms.h tss.h stab.h stab.def aout.h utils.h
  
! unassmbl.obj : build.h types.h gdt.h idt.h tss.h utils.h unassmbl.h syms.h mono.h
  
! utils.obj : build.h types.h tss.h gdt.h utils.h npx.h
  
! valloc.obj : build.h types.h valloc.h xms.h mono.h vcpi.h
  
  xms.obj : xms.h
  
! dalloc.obj : build.h types.h valloc.h dalloc.h mono.h
  
  mono.obj : mono.h
  
--- 66,92 ----
  
  # DEPENDENCIES
  
! debug.obj : types.h gdt.h tss.h utils.h unassmbl.h syms.h paging.h npx.h mono.h eventque.h
  
! exphdlr.obj : types.h gdt.h idt.h tss.h utils.h paging.h npx.h mono.h vcpi.h eventque.h 
  
! control.obj : types.h gdt.h idt.h tss.h valloc.h utils.h syms.h graphics.h mono.h vcpi.h
  
! graphics.obj : types.h paging.h graphics.h tss.h gdt.h driver.h
  
! paging.obj : types.h paging.h graphics.h tss.h idt.h gdt.h valloc.h dalloc.h utils.h aout.h mono.h vcpi.h
  
! syms.obj : types.h syms.h tss.h stab.h stab.def aout.h utils.h
  
! unassmbl.obj : types.h gdt.h idt.h tss.h utils.h unassmbl.h syms.h mono.h
  
! utils.obj : types.h tss.h gdt.h utils.h npx.h
  
! valloc.obj : types.h valloc.h xms.h mono.h vcpi.h
  
  xms.obj : xms.h
  
! dalloc.obj : types.h valloc.h dalloc.h mono.h
  
  mono.obj : mono.h
  
Only in orig: modi
diff -c3 orig/paging.c a/paging.c
*** orig/paging.c	Tue Jul  7 17:29:16 1992
--- a/paging.c	Mon Aug  3 01:05:48 1992
***************
*** 34,40 ****
  #include "mono.h"
  #include "vcpi.h"
  
! #define VERBOSE 0
  
  
  #if DEBUGGER
--- 34,40 ----
  #include "mono.h"
  #include "vcpi.h"
  
! //#define VERBOSE 0
  
  
  #if DEBUGGER
***************
*** 556,561 ****
--- 556,578 ----
        dread(paging_buffer, dblock);
        dfree(dblock);
        memput(vaddr, paging_buffer, 4096);
+       pt[pti] &= ~(word32)(PT_A | PT_D);  // clean dirty an accessed bits (set by memput)
+ #ifdef DEBUG
+       DEBUG(DEBUG_POUT) {
+ 
+          printf("\nPaging In %lx, flags = ", vaddr);
+    
+          printf("%c", (pt[pti] & PT_C) ? 'C' : ' ');
+          printf("%c", (pt[pti] & PT_S) ? 'S' : ' ');
+          printf("%c", (pt[pti] & PT_I) ? 'I' : ' ');
+          printf("%c", (pt[pti] & PT_D) ? 'D' : ' ');
+          printf("%c", (pt[pti] & PT_A) ? 'A' : ' ');
+          printf("%c", (pt[pti] & PT_U) ? 'U' : ' ');
+          printf("%c", (pt[pti] & PT_W) ? 'W' : ' ');
+          printf("%c", (pt[pti] & PT_P) ? 'P' : ' ');
+          printf("---");
+          }
+ #endif
      }
      else
      {
***************
*** 603,608 ****
--- 620,642 ----
      if (zaddr != -1)
        zero32(zaddr);
      memput(vtran, paging_buffer, vcnt);
+     pt[pti] &= ~(word32)(PT_A | PT_D);  // clean dirty and accessed bits (set by memput)
+ #ifdef DEBUG
+    DEBUG(DEBUG_PIN) {
+ 
+       printf("\nReading %lx, flags = ", vtran);
+ 
+       printf("%c", (pt[pti] & PT_C) ? 'C' : ' ');
+       printf("%c", (pt[pti] & PT_S) ? 'S' : ' ');
+       printf("%c", (pt[pti] & PT_I) ? 'I' : ' ');
+       printf("%c", (pt[pti] & PT_D) ? 'D' : ' ');
+       printf("%c", (pt[pti] & PT_A) ? 'A' : ' ');
+       printf("%c", (pt[pti] & PT_U) ? 'U' : ' ');
+       printf("%c", (pt[pti] & PT_W) ? 'W' : ' ');
+       printf("%c", (pt[pti] & PT_P) ? 'P' : ' ');
+       printf("---");
+       }
+ #endif
    }
  #if VERBOSE
    printf("\n");
***************
*** 614,619 ****
--- 648,655 ----
    return 0;
  }
  
+ static fInPageOutEverything = 0;
+ 
  static last_po_pdi = 0;
  static last_po_pti = 0;
  static last_pti = 0;
***************
*** 631,686 ****
    if (where == VA_640)
    {
      for (pti = last_pti+1; pti != last_pti; pti = (pti+1)%1024)
!       if ((vcpi_pt[pti] & (PT_P | PT_S)) == (PT_P | PT_S))
!       {
!         dblock = dalloc();
!         memcpy(paging_buffer, (void far *)(pti << 24), 4096);
!         dwrite(paging_buffer, dblock);
! #if VERBOSE
!         printf ("out_640 %d\n", pti);
  #endif
-         vcpi_pt[pti] &= 0xfff & ~PT_P; /* no longer present */
-         vcpi_pt[pti] |= (long)dblock << 12;
  #if TOPLINEINFO
!         update_status(old_status, 79);
  #endif
! 	last_pti = pti;
!         return pti;
!       }
      return -1;
    }
    pt = (word32 far *)((word32)(pd_seg[last_po_pdi]) << 24);
!   do {
!     if ((pd[last_po_pdi] & (PT_P | PT_S)) == (PT_P | PT_S))
!     {
!       if ((pt[last_po_pti] & (PT_P | PT_S)) == (PT_P | PT_S))
!       {
!         rv = pt[last_po_pti] >> 12;
!         dblock = dalloc();
!         v = ((word32)last_po_pdi << 22) | ((word32)last_po_pti << 12);
!         memget(v, paging_buffer, 4096);
!         dwrite(paging_buffer, dblock);
  #if VERBOSE
!         printf ("out %d:%d\r", last_po_pdi, last_po_pti);
  #endif
!         pt[last_po_pti] &= 0xfff & ~PT_P; /* no longer present */
!         pt[last_po_pti] |= (long)dblock << 12;
  #if TOPLINEINFO
!         update_status(old_status, 79);
  #endif
!         return rv;
!       }
!     }
!     else /* imagine we just checked the last entry */
!       last_po_pti = 1023;
!     if (++last_po_pti == 1024)
!     {
!       last_po_pti = 0;
!       if (++last_po_pdi == 1024)
!         last_po_pdi = 0;
!       pt = (word32 far *)((word32)(pd_seg[last_po_pdi]) << 24);
!     }
!   } while ((start_pdi != last_po_pdi) || (start_pti != last_po_pti));
  #if TOPLINEINFO
    update_status(old_status, 79);
  #endif
--- 667,927 ----
    if (where == VA_640)
    {
      for (pti = last_pti+1; pti != last_pti; pti = (pti+1)%1024)
!       if ((vcpi_pt[pti] & (PT_P | PT_S)) == (PT_P | PT_S)) {
! 
!          dblock = dalloc();
!          memcpy(paging_buffer, (void far *)(pti << 24), 4096);
!          dwrite(paging_buffer, dblock);
!          vcpi_pt[pti] &= 0xfff & ~PT_P; /* no longer present */
!          vcpi_pt[pti] |= (long)dblock << 12;
! 
! #if TOPLINEINFO
!          {
!          register int i;
!          char *pStr = "POut640";
!          for (i=0; pStr[i]; i++)
!             poke(screen_seg, i*2+50, pStr[i] | 0x0600);
!          }
! #endif
! #ifdef DEBUG
!          DEBUG(DEBUG_POUT) {
!             printf("\nPaging out 640 %lx, flags = ", ((word32)pti << 12));
! 
!             printf("%c", (vcpi_pt[pti] & PT_C) ? 'C' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_S) ? 'S' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_I) ? 'I' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_D) ? 'D' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_A) ? 'A' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_U) ? 'U' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_W) ? 'W' : ' ');
!             printf("%c", (vcpi_pt[pti] & PT_P) ? 'P' : ' ');
!             printf("---");
!             }
  #endif
  #if TOPLINEINFO
!          update_status(old_status, 79);
  #endif
! 	      last_pti = pti;
!          return pti;
!          }
      return -1;
    }
    pt = (word32 far *)((word32)(pd_seg[last_po_pdi]) << 24);
! 
! 
!    do {
!       if ((pd[last_po_pdi] & (PT_P | PT_S)) == (PT_P | PT_S)) {
! 
!          //
!          // Don't page out around current instruction
!          // UNLESS if paging out everything.
!          // Take a limit of +-4 pages
!          //
!          v = ((word32)last_po_pdi << 22) | ((word32)last_po_pti << 12);
! 
!          if (fInPageOutEverything == 0) {
! 
!             unsigned long eipReal = a_tss.tss_eip + 0x10000000L;
!             if ((v >= eipReal-0x4000) && (v <= eipReal+0x4000)) {
! 
! #ifdef DEBUG
!                DEBUG(DEBUG_SKIP_EIP)
!                   printf("\n++++++++++++++++ Skipping addr = %lx,  eip = %lx, pti = %u"
!                      , v, eipReal, last_po_pti
!                      );
! #endif
!                last_po_pti += 8;
!                if (last_po_pti >= 1024) {
! 
! #ifdef DEBUG
!                   DEBUG(DEBUG_SKIP_EIP)
!                      printf("\n                Wrapped, pti = %u, pdi = %u"
!                         , last_po_pti, last_po_pdi);
! #endif
! 
!                   last_po_pti = last_po_pti % 1024;
! 
!                   if (++last_po_pdi == 1024)
!                      last_po_pdi = 0;
!                   else if ((pd[last_po_pdi] & (PT_P | PT_S)) != (PT_P | PT_S))
!                      while ((pd[last_po_pdi] & (PT_P | PT_S)) != (PT_P | PT_S)) {
!                         last_po_pdi++;
!                         if ((pd[last_po_pdi] & (PT_P | PT_S)) == (PT_P | PT_S))
!                            break;
!                         }
! 
!                   pt = (word32 far *)((word32)(pd_seg[last_po_pdi]) << 24);
!                   }
!                v = ((word32)last_po_pdi << 22) | ((word32)last_po_pti << 12);
!                }
!             }   
! 
!          if ((pt[last_po_pti] & (PT_P | PT_S)) == (PT_P | PT_S)) {
! 
!             // v = ((word32)last_po_pdi << 22) | ((word32)last_po_pti << 12);
! 
!             //--------------------- TEXT -----------------------------
!             // Text is read only, so discard page
!             //
!             if ((v >= areas[A_text].first_addr) &&
!                   (v <= areas[A_text].last_addr) ) {
! 
!                rv = pt[last_po_pti] >> 12;
!                pt[last_po_pti] &= 0xfff & ~(PT_A | PT_D | PT_P | PT_I);
! #ifdef DEBUG
!                DEBUG(DEBUG_POUT_DISCARD) {
!                   printf("\nDiscarding Text %lx, flags = ", v);
! 
!                   printf("%c", (pt[last_po_pti] & PT_C) ? 'C' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_S) ? 'S' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_I) ? 'I' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_D) ? 'D' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_A) ? 'A' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_U) ? 'U' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_W) ? 'W' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_P) ? 'P' : ' ');
!                   printf("---");
!                   }
! #endif
! #if TOPLINEINFO
!                {
!                register int i;
!                char *pStr = "Discard";
!                for (i=0; pStr[i]; i++)
!                   poke(screen_seg, i*2+50, pStr[i] | 0x0400);
!                }
! #endif
!                }
!             //
!             //--------------------- DATA -----------------------------
!             // Candidate is a data page that is NOT a split page data / bss
!             //
!             else if ((v >= areas[A_data].first_addr)  &&
!                      (v <= areas[A_data].last_addr)   &&
!                      ((v & 0xfffff000L) != (areas[A_bss].first_addr & 0xfffff000L))
!                   ) {
!                //
!                // Selected page was modified before. Can't be discarded
!                //
!                if (pt[last_po_pti] & PT_PageOnceDirty) {
! #ifdef DEBUG
!                   DEBUG(DEBUG_POUT_DATA_DIRTY)
!                      printf("\n------- Encountered Data page DIRTY %lx", v);
! #endif
!                   goto PageItOut;   // I can't believe I am using goto
!                   }
!                //
!                // Selected page was just modified. Can't be discarded
!                //
!                else if (pt[last_po_pti] & PT_D) {
!                   pt[last_po_pti] |= PT_PageOnceDirty;
! #ifdef DEBUG
!                   DEBUG(DEBUG_POUT_DATA_DIRTY) {
!                      printf("\n---------------- Marking Data page Once DIRTY %lx, flags =", v);
! 
!                      printf("%c", (pt[last_po_pti] & PT_C) ? 'C' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_S) ? 'S' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_I) ? 'I' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_D) ? 'D' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_A) ? 'A' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_U) ? 'U' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_W) ? 'W' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_P) ? 'P' : ' ');
!                      printf("---");
!                      }
! #endif
!                   goto PageItOut;
!                   }
!                //
!                // Page was never written to. Discard it
!                //
!                else {
! 
!                   rv = pt[last_po_pti] >> 12;
!                   pt[last_po_pti] &= 0xfff & ~(PT_A | PT_D | PT_P | PT_I | PT_PageOnceDirty);
! 
! #ifdef DEBUG
!                   DEBUG(DEBUG_POUT_DISCARD) {
!                      printf("\nDiscarding Data %lx, flags = ", v);
! 
!                      printf("%c", (pt[last_po_pti] & PT_C) ? 'C' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_S) ? 'S' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_I) ? 'I' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_D) ? 'D' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_A) ? 'A' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_U) ? 'U' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_W) ? 'W' : ' ');
!                      printf("%c", (pt[last_po_pti] & PT_P) ? 'P' : ' ');
!                      printf("+++++++++++++++ ");
!                      }
! #endif
! #if TOPLINEINFO
!                   {
!                   register int i;
!                   char *pStr = "Dsc Dta";
!                   for (i=0; pStr[i]; i++)
!                      poke(screen_seg, i*2+50, pStr[i] | 0x0400);
!                   }
! #endif
!                   }
!                }
!             //
!             // Page out to swap file
!             //
!             else {
! 
! PageItOut:
!                rv = pt[last_po_pti] >> 12;
!                dblock = dalloc();
!                memget(v, paging_buffer, 4096);
!                dwrite(paging_buffer, dblock);
!                pt[last_po_pti] &= 0xfff & ~(PT_A | PT_D | PT_P); /* no longer present */
!                pt[last_po_pti] |= (long)dblock << 12;
! 
! #ifdef DEBUG
!                DEBUG(DEBUG_POUT) {
!                   printf("\nPaging out %lx, flags = ", v);
! 
!                   printf("%c", (pt[last_po_pti] & PT_C) ? 'C' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_S) ? 'S' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_I) ? 'I' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_D) ? 'D' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_A) ? 'A' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_U) ? 'U' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_W) ? 'W' : ' ');
!                   printf("%c", (pt[last_po_pti] & PT_P) ? 'P' : ' ');
!                   printf("---");
!                   }
! #endif
! #if TOPLINEINFO
!                {
!                register int i;
!                char *pStr = "POut   ";
!                for (i=0; pStr[i]; i++)
!                   poke(screen_seg, i*2+50, pStr[i] | 0x0600);
!                }
! #endif
  #if VERBOSE
!                printf ("out %d:%d\r", last_po_pdi, last_po_pti);
  #endif
!                }
  #if TOPLINEINFO
!             update_status(old_status, 79);
  #endif
!             return rv;
!             }
!          }
!       else /* imagine we just checked the last entry */
!          last_po_pti = 1023;
! 
!       if (++last_po_pti == 1024) {
!          last_po_pti = 0;
!          if (++last_po_pdi == 1024)
!          last_po_pdi = 0;
!          pt = (word32 far *)((word32)(pd_seg[last_po_pdi]) << 24);
!          }
!    } while ((start_pdi != last_po_pdi) || (start_pti != last_po_pti));
! 
  #if TOPLINEINFO
    update_status(old_status, 79);
  #endif
***************
*** 698,703 ****
--- 939,952 ----
    unsigned pn;
    unsigned ptb;
    void far *fp;
+ 
+ #ifdef DEBUG
+    DEBUG(DEBUG_POUT)
+       printf("\nPage Out everything -------------------");
+ #endif
+ 
+    fInPageOutEverything = 1;
+ 
    while ((pn=page_out(-1)) != 0xffff)
    {
      vfree();
***************
*** 732,737 ****
--- 981,994 ----
    unsigned ptb;
    word32 far *pt;
    unsigned pta;
+ 
+ 
+ #ifdef DEBUG
+    DEBUG(DEBUG_PIN)
+       printf("\nPage In everything -------------------");
+ #endif
+    fInPageOutEverything = 0;
+ 
    valloc_initted = 0;
    pta = valloc(VA_640);
    pd = (word32 far *)((word32)pta << 24);
diff -c3 orig/paging.h a/paging.h
*** orig/paging.h	Tue Jul  7 17:29:20 1992
--- a/paging.h	Sun Aug  2 18:20:54 1992
***************
*** 25,30 ****
--- 25,32 ----
  #define PT_S	0x400	/* Swappable (else not) */
  #define	PT_C	0x800	/* Candidate for swapping */
  
+ #define PT_PageOnceDirty   PT_C  // Page was modified by user at least once
+ 
  #define EMU_TEXT 0xb0000000
  
  /*  If not present and initialized, page is in swap file.

-------- END CUT -----------------------------------