src/lib/16_mm.c

   1 /* Catacomb Apocalypse Source Code
   2  * Copyright (C) 1993-2014 Flat Rock Software
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 // NEWMM.C
  20
  21 /*
  22 =============================================================================
  23
  24                         ID software memory manager
  25                         --------------------------
  26
  27 Primary coder: John Carmack
  28
  29 RELIES ON
  30 ---------
  31 Quit (char *error) function
  32
  33
  34 WORK TO DO
  35 ----------
  36 MM_SizePtr to change the size of a given pointer
  37
  38 Multiple purge levels utilized
  39
  40 EMS / XMS unmanaged routines
  41
  42 =============================================================================
  43 */
  44 /*
  45
  46 Open Watcom port by sparky4
  47
  48 */
  49 #include "src/lib/16_mm.h"
  50 #pragma hdrstop
  51
  52 #pragma warn -pro
  53 #pragma warn -use
  54
  55 /*
  56 =============================================================================
  57
  58                                                  GLOBAL VARIABLES
  59
  60 =============================================================================
  61 */
  62
  63 void            (* beforesort) (void);
  64 void            (* aftersort) (void);
  65 void            (* XMSaddr) (void);             // far pointer to XMS driver
  66
  67 /*
  68 =============================================================================
  69
  70                                                  LOCAL VARIABLES
  71
  72 =============================================================================
  73 */
  74
  75 static  char *ParmStringsexmm[] = {"noems","noxms",""};
  76
  77 /*
  78 ======================
  79 =
  80 = MML_CheckForEMS
  81 =
  82 = Routine from p36 of Extending DOS
  83 =
  84 =======================
  85 */
  86
  87 boolean MML_CheckForEMS(void)
  88 {
  89         boolean emmcfems;
  90         static char     emmname[] = "EMMXXXX0"; //fix by andrius4669
  91 //              mov     dx,OFFSET emmname
  92         __asm {
  93                 //LEA   DX, emmname     //fix by andrius4669
  94                 mov     dx,OFFSET emmname       //fix by andrius4669
  95                 mov     ax,0x3d00
  96                 int     0x21            // try to open EMMXXXX0 device
  97                 jc      error
  98
  99                 mov     bx,ax
 100                 mov     ax,0x4400
 101
 102                 int     0x21            // get device info
 103                 jc      error
 104
 105                 and     dx,0x80
 106                 jz      error
 107
 108                 mov     ax,0x4407
 109
 110                 int     0x21            // get status
 111                 jc      error
 112                 or      al,al
 113                 jz      error
 114
 115                 mov     ah,0x3e
 116                 int     0x21            // close handle
 117                 jc      error
 118                 //
 119                 // EMS is good
 120                 //
 121                 mov     emmcfems,1
 122                 jmp End
 123                 error:
 124                 //
 125                 // EMS is bad
 126                 //
 127                 mov     emmcfems,0
 128                 End:
 129         }
 130         return(emmcfems);
 131 }
 132
 133
 134 /*
 135 ======================
 136 =
 137 = MML_SetupEMS
 138 =
 139 =======================
 140 */
 141
 142 byte MML_SetupEMS(mminfo_t *mm)
 143 {
 144         byte    str[160];
 145         byte    err;
 146         boolean errorflag=false;
 147
 148         unsigned int EMSVer = 0;
 149         //byte  EMS_status;
 150         unsigned        totalEMSpages,freeEMSpages,EMSpageframe,EMSpagesmapped,EMShandle;
 151         totalEMSpages = freeEMSpages = EMSpageframe = EMSpagesmapped = 0;
 152
 153         __asm
 154                 {
 155                 mov     ah,EMS_STATUS
 156                 int     EMS_INT                                         // make sure EMS hardware is present
 157                 or      ah,ah
 158                 //mov   [EMS_status],ah
 159                 jnz     error
 160
 161                 mov     ah,EMS_VERSION
 162                 int     EMS_INT
 163                 or      ah,ah
 164                 jnz     error
 165                 mov     [EMSVer],ax                             //      set EMSVer
 166                 cmp     al,0x32                                         // only work on ems 3.2 or greater
 167                 jb      error
 168
 169                 mov     ah,EMS_GETFRAME
 170                 int     EMS_INT                                         // find the page frame address
 171                 or      ah,ah
 172                 jnz     error
 173                 mov     [EMSpageframe],bx
 174
 175                 mov     ah,EMS_GETPAGES
 176                 int     EMS_INT                                         // find out how much EMS is there
 177                 or      ah,ah
 178                 jnz     error
 179                 mov     [totalEMSpages],dx
 180                 mov     [freeEMSpages],bx
 181                 or      bx,bx
 182                 jz      noEMS                                           // no EMS at all to allocate
 183                                                                                         //EXPAND DONG!!!!
 184                 cmp     [EMSVer],0x40
 185                 jb      low
 186                 cmp     bx,[freeEMSpages]
 187                 jle     getpages
 188                 mov     bx,[freeEMSpages]
 189                 jmp     getpages
 190
 191 low:
 192                 cmp     bx,4
 193                 jle     getpages                                        // there is only 1,2,3,or 4 pages
 194                 mov     bx,4                                            // we can't use more than 4 pages
 195
 196 getpages:
 197                 mov     [EMSpagesmapped],bx
 198                 mov     ah,EMS_ALLOCPAGES                       // allocate up to 64k of EMS
 199                 int     EMS_INT
 200                 or      ah,ah
 201                 jnz     error
 202                 mov     [EMShandle],dx
 203                 jmp End
 204 error:
 205                 mov     err,ah
 206                 mov     errorflag,1
 207                 jmp End
 208 noEMS:
 209 End:
 210         }
 211         if(errorflag==true)
 212         {
 213                 //err = CPURegs.h.ah;
 214                 strcpy(str,"MM_SetupEMS: EMS error ");
 215                 //itoa(err,str2,16);
 216                 MM_EMSerr(&str, err);
 217                 printf("%s\n",str);
 218                 return err;
 219         }
 220         mm->totalEMSpages=totalEMSpages;
 221         mm->freeEMSpages=freeEMSpages;
 222         mm->EMSpageframe=EMSpageframe;
 223         mm->EMSpagesmapped=EMSpagesmapped;
 224         mm->EMShandle=EMShandle;
 225         mm->EMSVer=EMSVer;
 226         return 0;
 227 }
 228
 229
 230 /*
 231 ======================
 232 =
 233 = MML_ShutdownEMS
 234 =
 235 =======================
 236 */
 237
 238 void MML_ShutdownEMS(mminfo_t *mm)
 239 {
 240         boolean errorflag=false;
 241         unsigned EMShandle=mm->EMShandle;
 242
 243         if(!EMShandle)
 244                 return;
 245         __asm
 246         {
 247                 mov     ah,EMS_FREEPAGES
 248                 mov     dx,[EMShandle]
 249                 int     EMS_INT
 250                 or      ah,ah
 251                 jz      ok
 252                 mov     errorflag,1
 253                 ok:
 254         }
 255         if(errorflag==true) printf("MML_ShutdownEMS: Error freeing EMS!\n");    //++++ add something
 256 }
 257
 258 /*
 259 ====================
 260 =
 261 = MM_MapEMS
 262 =
 263 = Maps the 64k of EMS used by memory manager into the page frame
 264 = for general use.  This only needs to be called if you are keeping
 265 = other things in EMS.
 266 =
 267 ====================
 268 */
 269
 270 byte MM_MapEMS(mminfo_t *mm, mminfotype *mmi)
 271 {
 272         byte    str[160];
 273         unsigned        EMShandle;
 274         byte err;
 275         boolean errorflag=false;
 276         int     i;
 277         EMShandle=mm->EMShandle;
 278
 279         for (i=0;i<4/*MAPPAGES*/;i++)
 280         {
 281                 __asm
 282                 {
 283                         mov     ah,EMS_MAPPAGE
 284                         mov     bx,[i]                  // logical page
 285                         mov     al,bl                   // physical page
 286                         mov     dx,[EMShandle]  // handle
 287                         int     EMS_INT
 288                         or      ah,ah
 289                         jnz     error
 290                         jmp End
 291                         error:
 292                         mov     err,ah
 293                         mov     errorflag,1
 294                         End:
 295                 }
 296                 if(errorflag==true)
 297                 {
 298                         //err = CPURegs.h.ah;
 299                         strcpy(str,"MM_MapEMS: EMS error ");
 300                         //itoa(err,str2,16);
 301                         MM_EMSerr(str, err);
 302                         printf("%s\n",str);
 303                         //printf("FACK! %x\n", err);
 304                         return err;
 305                 }
 306         }
 307         mmi->EMSmem = (i)*0x4000lu;
 308         return 0;
 309 }
 310
 311 byte MM_MapXEMS(mminfo_t *mm, mminfotype *mmi)
 312 {
 313 //SUB EMS.MapXPages (PhysicalStart, LogicalStart, NumPages, Handle)
 314
 315         //Maps up to 4 logical EMS pages to physical pages in the page frame, where:
 316         //PhysicalStart = Physical page first logical page is mapped to
 317         //LogicalStart  = First logical page to map
 318         //NumPages      = Number of pages to map (1 to 4)
 319         //Handle        = EMS handle logical pages are allocated to
 320
 321   /*//Create a buffer containing the page information
 322 //  FOR x = 0 TO NumPages - 1
 323 //    MapInfo$ = MapInfo$ + MKI$(LogicalStart + x) + MKI$(PhysicalStart + x)
 324 //  NEXT*/
 325
 326 //  Regs.ax = 0x5000                           //Map the pages in the buffer
 327 //  Regs.cx = NumPages                         //to the pageframe
 328 //  Regs.dx = Handle
 329 //  Regs.ds = VARSEG(MapInfo$)
 330 //  Regs.si = SADD(MapInfo$)
 331 //  InterruptX 0x67, Regs, Regs
 332 //      EMS.Error = (Regs.ax AND 0xFF00&) \ 0x100  //Store the status code
 333
 334 //END SUB
 335         byte    str[160];
 336         byte err;
 337         word    EMShandle;
 338         boolean errorflag=false;
 339         int     i;
 340         EMShandle=mm->EMShandle;
 341
 342         if(mm->EMSVer<0x40)
 343                 return 5;
 344
 345         for (i=0;i<MAPPAGES;i++)
 346         {
 347                 __asm
 348                 {
 349                         mov     ah,EMS_MAPXPAGE
 350                         mov     cx,[i]                  // logical page
 351                         mov     al,bl                   // physical page
 352                         mov     dx,[EMShandle]  // handle
 353                         int     EMS_INT
 354                         or      ah,ah
 355                         jnz     error
 356                         jmp End
 357                         error:
 358                         mov     err,ah
 359                         mov     errorflag,1
 360                         End:
 361                 }
 362                 if(errorflag==true)
 363                 {
 364                         //err = CPURegs.h.ah;
 365                         //strcpy(str,"MM_MapXEMS: EMS error 0x");
 366                         strcpy(str,"MM_MapXEMS: EMS error ");
 367                         //itoa(err,str2,16);
 368                         MM_EMSerr(&str, err);
 369                         printf("%s\n",str);
 370                         //printf("%s%x\n",str, err);
 371                         //printf("FACK! %x\n", err);
 372                         return err;
 373                 }
 374         }
 375         mmi->EMSmem = (i)*0x4000lu;
 376         return 0;
 377 }
 378
 379 //==========================================================================
 380
 381 /*
 382 ======================
 383 =
 384 = MML_CheckForXMS
 385 =
 386 = Check for XMM driver
 387 =
 388 =======================
 389 */
 390
 391 boolean MML_CheckForXMS(mminfo_t *mm)
 392 {
 393         boolean errorflag=false;
 394         mm->numUMBs = 0;
 395
 396         __asm
 397         {
 398                 mov     ax,0x4300
 399                 int     0x2f                            // query status of installed diver
 400                 cmp     al,0x80
 401                 je      good
 402                 mov     errorflag,1
 403                 good:
 404         }
 405         if(errorflag==true) return false;
 406         else return true;
 407 }
 408
 409
 410 /*
 411 ======================
 412 =
 413 = MML_SetupXMS
 414 =
 415 = Try to allocate all upper memory block
 416 =
 417 =======================
 418 */
 419
 420 void MML_SetupXMS(mminfo_t *mm, mminfotype *mmi)
 421 {
 422         unsigned        base,size;
 423
 424 getmemory:
 425         __asm
 426         {
 427                 mov     ax,0x4310
 428                 int     0x2f
 429                 mov     [WORD PTR XMSaddr],bx
 430                 mov     [WORD PTR XMSaddr+2],es         // function pointer to XMS driver
 431
 432                 mov     ah,XMS_ALLOCUMB
 433                 mov     dx,0xffff                                       // try for largest block possible
 434                 //mov     ax,dx                                         // Set available Kbytes.
 435                 call    [DWORD PTR XMSaddr]
 436                 or      ax,ax
 437                 jnz     gotone
 438
 439                 cmp     bl,0xb0                                         // error: smaller UMB is available
 440                 jne     done;
 441
 442                 mov     ah,XMS_ALLOCUMB
 443                 call    [DWORD PTR XMSaddr]             // DX holds largest available UMB
 444                 or      ax,ax
 445                 jz      done                                            // another error...
 446
 447 gotone:
 448                 mov     [base],bx
 449                 mov     [size],dx
 450 done:
 451         }
 452         printf("base=%u ", base); printf("size=%u\n", size);
 453         MML_UseSpace(base,size, mm);
 454         mmi->XMSmem += size*16;
 455         mm->UMBbase[mm->numUMBs] = base;
 456         mm->numUMBs++;
 457         if(mm->numUMBs < MAXUMBS)
 458                 goto getmemory;
 459 }
 460
 461
 462 /*
 463 ======================
 464 =
 465 = MML_ShutdownXMS
 466 =
 467 ======================
 468 */
 469
 470 void MML_ShutdownXMS(mminfo_t *mm)
 471 {
 472         int     i;
 473         unsigned        base;
 474
 475         for (i=0;i<mm->numUMBs;i++)
 476         {
 477                 base = mm->UMBbase[i];
 478                 __asm
 479                 {
 480                         mov     ah,XMS_FREEUMB
 481                         mov     dx,[base]
 482                         call    [DWORD PTR XMSaddr]
 483                 }
 484         }
 485 }
 486
 487 //==========================================================================
 488
 489 /*
 490 ======================
 491 =
 492 = MML_UseSpace
 493 =
 494 = Marks a range of paragraphs as usable by the memory manager
 495 = This is used to mark space for the near heap, far heap, ems page frame,
 496 = and upper memory blocks
 497 =
 498 ======================
 499 */
 500
 501 void MML_UseSpace(/*d*/word segstart, dword seglength, mminfo_t *mm)
 502 {
 503         mmblocktype huge *scan,huge *last;
 504         word            segm;
 505         dword   oldend;
 506         dword           extra;
 507
 508         scan = last = mm->mmhead;
 509         mm->mmrover = mm->mmhead;               // reset rover to start of memory
 510
 511 //
 512 // search for the block that contains the range of segments
 513 //
 514         while(scan->start+scan->length < segstart)
 515         {
 516                 last = scan;
 517                 scan = scan->next;
 518         }
 519
 520         //find out how many blocks it spans!
 521         if(seglength>0xffffu)
 522         {
 523 //              segm=seglength/0x4000u;
 524                 segm=seglength/0xffffu;
 525         }
 526         else segm=1;
 527
 528         //++++emsver stuff!
 529         if(segm>1/*extra>0xfffflu*/)
 530         {
 531                 /*__asm
 532                 {
 533                         push    ds
 534                         mov     ax,ds
 535                         inc             ax
 536                         mov     ds,ax
 537                 }*/
 538
 539
 540 //MML_UseSpace(?segstart?, ?length?, mm);
 541
 542                 /*__asm
 543                 {
 544                         pop ds
 545                 }*/
 546                 //printf("MML_UseSpace: Segment spans two blocks!\n");
 547         }
 548
 549 //
 550 // take the given range out of the block
 551 //
 552         oldend = scan->start + scan->length;
 553         extra = oldend - (segstart+seglength);
 554 /*
 555 printf("segm=%u ", segm);
 556 printf("ex=%lu  ", extra);
 557 printf("start+seglen=%lu        ", segstart+seglength);
 558 printf("len=%u  ", scan->length);
 559 printf("segsta=%x       ", segstart);
 560 printf("seglen=%lu\n", seglength);
 561 */
 562 //segu:
 563 //++++todo: linked list of segment!
 564 //printf("segm=%lu\n", segm);
 565         if(segstart == scan->start)
 566         {
 567                 last->next = scan->next;                        // unlink block
 568                 MM_FreeBlock(scan, mm);
 569                 scan = last;
 570         }
 571         else
 572                 scan->length = segstart-scan->start;    // shorten block
 573
 574 //      segm--;
 575
 576         if(extra > 0)
 577         {
 578                 MM_GetNewBlock(mm);
 579                 mm->mmnew->next = scan->next;
 580                 scan->next = mm->mmnew;
 581                 mm->mmnew->start = segstart+seglength;
 582                 mm->mmnew->length = extra;
 583                 mm->mmnew->attributes = LOCKBIT;
 584         }//else if(segm>0) goto segu;
 585
 586 }
 587
 588 //==========================================================================
 589
 590 /*
 591 ====================
 592 =
 593 = MML_ClearBlock
 594 =
 595 = We are out of blocks, so free a purgable block
 596 =
 597 ====================
 598 */
 599
 600 void MML_ClearBlock(mminfo_t *mm)
 601 {
 602         mmblocktype huge *scan,huge *last;
 603
 604         scan = mm->mmhead->next;
 605
 606         while(scan)
 607         {
 608                 if(!(scan->attributes&LOCKBIT) && (scan->attributes&PURGEBITS))
 609                 {
 610                         MM_FreePtr(scan->useptr, mm);
 611                         return;
 612                 }
 613                 scan = scan->next;
 614         }
 615
 616         printf("MM_ClearBlock: No purgable blocks!\n");
 617 }
 618
 619
 620 //==========================================================================
 621
 622 /*
 623 ===================
 624 =
 625 = MM_Startup
 626 =
 627 = Grabs all space from turbo with malloc/farmalloc
 628 = Allocates bufferseg misc buffer
 629 =
 630 ===================
 631 */
 632
 633 void MM_Startup(mminfo_t *mm, mminfotype *mmi)
 634 {
 635         int i;
 636         dword length,seglength;
 637         //dword length; word seglength;
 638         void huge       *start;
 639         word    segstart;//,endfree;
 640
 641         if(mm->mmstarted)
 642                 MM_Shutdown(mm);
 643
 644         mm->mmstarted = true;
 645         mm->bombonerror = true;
 646
 647 //
 648 // set up the linked list (everything in the free list;
 649 //
 650         //printf("              linked list making!\n");
 651         mm->mmhead = NULL;
 652         mm->mmfree = &(mm->mmblocks[0]);
 653         for(i=0;i<MAXBLOCKS-1;i++)
 654         {
 655                 mm->mmblocks[i].next = &(mm->mmblocks[i+1]);
 656         }
 657         mm->mmblocks[i].next = NULL;
 658
 659 //
 660 // locked block of all memory until we punch out free space
 661 //
 662         //printf("              newblock making!\n");
 663         MM_GetNewBlock(mm);
 664         mm->mmhead = mm->mmnew;                         // this will allways be the first node
 665         mm->mmnew->start = 0;
 666         mm->mmnew->length = 0xffff;
 667         mm->mmnew->attributes = LOCKBIT;
 668         mm->mmnew->next = NULL;
 669         mm->mmrover = mm->mmhead;
 670
 671 //
 672 // get all available near conventional memory segments
 673 //
 674 //----  length=coreleft();
 675         printf("                nearheap making!\n");
 676         _heapgrow();
 677         length=_memmax();//(dword)GetFreeSize();
 678         start = (void huge *)(mm->nearheap = malloc(length));
 679         length -= 16-(FP_OFF(start)&15);
 680         length -= SAVENEARHEAP;
 681         seglength = length / 16;                        // now in paragraphs
 682         segstart = FP_SEG(start)+(FP_OFF(start)+15)/16;
 683         MML_UseSpace(segstart,seglength, mm);
 684         mmi->nearheap = length;
 685         printf("start=%FP       segstart=%X     seglen=%lu      len=%lu\n", start, segstart, seglength, length);
 686         printf("                near heap ok!\n");
 687
 688 //
 689 // get all available far conventional memory segments
 690 //
 691 //----  length=farcoreleft();
 692         printf("                farheap making!\n");
 693         _fheapgrow();
 694         length=(dword)GetFarFreeSize();//0xffffUL*4UL;
 695         //start = mm->farheap = halloc(length, 1);
 696         start = mm->farheap = _fmalloc(length);
 697         length -= 16-(FP_OFF(start)&15);
 698         length -= SAVEFARHEAP;
 699         seglength = length / 16;                        // now in paragraphs
 700         segstart = FP_SEG(start)+(FP_OFF(start)+15)/16;
 701         MML_UseSpace(segstart,seglength, mm);
 702         mmi->farheap = length;
 703         printf("start=%FP       segstart=%X     seglen=%lu      len=%lu\n", start, segstart, seglength, length);
 704         printf("                far heap ok!\n");
 705
 706         mmi->mainmem = mmi->nearheap + mmi->farheap;
 707
 708         getch();
 709
 710 //
 711 // detect EMS and allocate up to 64K at page frame
 712 //
 713 printf("                EMS1\n");
 714 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 715         mmi->EMSmem = 0;
 716         for(i = 1;i < __argc;i++)
 717         {
 718                 if(US_CheckParm(__argv[i],ParmStringsexmm) == 0)
 719                         goto emsskip;                           // param NOEMS
 720         }
 721 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 722         if(MML_CheckForEMS())
 723         {
 724 printf("                EMS2\n");
 725 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 726                 MML_SetupEMS(mm);                                       // allocate space
 727 printf("                EMS3\n");
 728 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 729                 //TODO: EMS4! AND EMS 3.2 MASSIVE DATA HANDLMENT!
 730                 MML_UseSpace(mm->EMSpageframe,(MAPPAGES)*0x4000lu, mm);
 731 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 732 printf("                EMS4\n");
 733                 //if(mm->EMSVer<0x40)
 734                         MM_MapEMS(mm, mmi);                                     // map in used pages
 735                 //else
 736                         //MM_MapXEMS(mm, mmi);                                  // map in used pages
 737         }
 738
 739 //
 740 // detect XMS and get upper memory blocks
 741 //
 742 emsskip:
 743         mmi->XMSmem = 0;
 744         for(i = 1;i < __argc;i++)
 745         {
 746                 if(US_CheckParm(__argv[i],ParmStringsexmm) == 0)
 747                         goto xmsskip;                           // param NOXMS
 748         }
 749 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 750         if(MML_CheckForXMS(mm))
 751         {
 752 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 753 printf("                XMS!\n");
 754                 MML_SetupXMS(mm, mmi);                                  // allocate as many UMBs as possible
 755         }
 756
 757 //
 758 // allocate the misc buffer
 759 //
 760 xmsskip:
 761         mm->mmrover = mm->mmhead;               // start looking for space after low block
 762
 763         MM_GetPtr(&(mm->bufferseg),BUFFERSIZE, mm, mmi);
 764 }
 765
 766 //==========================================================================
 767
 768 /*
 769 ====================
 770 =
 771 = MM_Shutdown
 772 =
 773 = Frees all conventional, EMS, and XMS allocated
 774 =
 775 ====================
 776 */
 777
 778 void MM_Shutdown(mminfo_t *mm)
 779 {
 780         if(!(mm->mmstarted))
 781                 return;
 782
 783         _ffree(mm->farheap);    printf("                far freed\n");
 784         free(mm->nearheap);     printf("                near freed\n");
 785         if(MML_CheckForEMS()){ MML_ShutdownEMS(mm); printf("            EMS freed\n"); }
 786         if(MML_CheckForXMS(mm)){ MML_ShutdownXMS(mm); printf("          XMS freed\n"); }
 787 }
 788
 789 //==========================================================================
 790
 791 /*
 792 ====================
 793 =
 794 = MM_GetPtr
 795 =
 796 = Allocates an unlocked, unpurgable block
 797 =
 798 ====================
 799 */
 800
 801 void MM_GetPtr(memptr *baseptr,dword size, mminfo_t *mm, mminfotype *mmi)
 802 {
 803         mmblocktype huge *scan,huge *lastscan,huge *endscan,huge *purge,huge *next;
 804         int                     search;
 805         unsigned        needed,startseg;
 806
 807         needed = (size+15)/16;          // convert size from bytes to paragraphs
 808
 809         MM_GetNewBlock(mm);                             // fill in start and next after a spot is found
 810         mm->mmnew->length = needed;
 811         mm->mmnew->useptr = baseptr;
 812         mm->mmnew->attributes = BASEATTRIBUTES;
 813
 814         for(search = 0; search<3; search++)
 815         {
 816         //
 817         // first search:        try to allocate right after the rover, then on up
 818         // second search:       search from the head pointer up to the rover
 819         // third search:        compress memory, then scan from start
 820                 if(search == 1 && mm->mmrover == mm->mmhead)
 821                         search++;
 822
 823                 switch(search)
 824                 {
 825                 case 0:
 826                         lastscan = mm->mmrover;
 827                         scan = mm->mmrover->next;
 828                         endscan = NULL;
 829                         break;
 830                 case 1:
 831                         lastscan = mm->mmhead;
 832                         scan = mm->mmhead->next;
 833                         endscan = mm->mmrover;
 834                         break;
 835                 case 2:
 836                         MM_SortMem(mm);
 837                         lastscan = mm->mmhead;
 838                         scan = mm->mmhead->next;
 839                         endscan = NULL;
 840                         break;
 841                 }
 842
 843                 startseg = lastscan->start + lastscan->length;
 844
 845                 while(scan != endscan)
 846                 {
 847                         if(scan->start - startseg >= needed)
 848                         {
 849                         //
 850                         // got enough space between the end of lastscan and
 851                         // the start of scan, so throw out anything in the middle
 852                         // and allocate the new block
 853                         //
 854                                 purge = lastscan->next;
 855                                 lastscan->next = mm->mmnew;
 856                                 mm->mmnew->start = *(unsigned *)baseptr = startseg;
 857                                 mm->mmnew->next = scan;
 858                                 while(purge != scan)
 859                                 {       // free the purgable block
 860                                         next = purge->next;
 861                                         MM_FreeBlock(purge, mm);
 862                                         purge = next;           // purge another if not at scan
 863                                 }
 864                                 mm->mmrover = mm->mmnew;
 865                                 return; // good allocation!
 866                         }
 867
 868                         //
 869                         // if this block is purge level zero or locked, skip past it
 870                         //
 871                         if((scan->attributes & LOCKBIT)
 872                                 || !(scan->attributes & PURGEBITS) )
 873                         {
 874                                 lastscan = scan;
 875                                 startseg = lastscan->start + lastscan->length;
 876                         }
 877
 878
 879                         scan=scan->next;                // look at next line
 880                 }
 881         }
 882
 883         if (mm->bombonerror)
 884         {
 885                 printf(OUT_OF_MEM_MSG,(size-mmi->nearheap));
 886                 exit(-5);
 887         }
 888         else
 889                 mm->mmerror = true;
 890 }
 891
 892 //==========================================================================
 893
 894 /*
 895 ====================
 896 =
 897 = MM_FreePtr
 898 =
 899 = Allocates an unlocked, unpurgable block
 900 =
 901 ====================
 902 */
 903
 904 void MM_FreePtr(memptr *baseptr, mminfo_t *mm)
 905 {
 906         mmblocktype huge *scan,huge *last;
 907
 908         last = mm->mmhead;
 909         scan = last->next;
 910
 911         if(baseptr == mm->mmrover->useptr)      // removed the last allocated block
 912                 mm->mmrover = mm->mmhead;
 913
 914         while(scan->useptr != baseptr && scan)
 915         {
 916                 last = scan;
 917                 scan = scan->next;
 918         }
 919
 920         if(!scan)
 921         {
 922                 printf("MM_FreePtr: Block not found!\n");
 923                 return;
 924         }
 925
 926         last->next = scan->next;
 927
 928         MM_FreeBlock(scan, mm);
 929 }
 930 //==========================================================================
 931
 932 /*
 933 =====================
 934 =
 935 = MM_SetPurge
 936 =
 937 = Sets the purge level for a block (locked blocks cannot be made purgable)
 938 =
 939 =====================
 940 */
 941
 942 void MM_SetPurge(memptr *baseptr, int purge, mminfo_t *mm)
 943 {
 944         mmblocktype huge *start;
 945
 946         start = mm->mmrover;
 947
 948         do
 949         {
 950                 if(mm->mmrover->useptr == baseptr)
 951                         break;
 952
 953                 mm->mmrover = mm->mmrover->next;
 954
 955                 if(!mm->mmrover)
 956                         mm->mmrover = mm->mmhead;
 957                 else if(mm->mmrover == start)
 958                 {
 959                         printf("MM_SetPurge: Block not found!");
 960                         return;
 961                 }
 962
 963         } while(1);
 964
 965         mm->mmrover->attributes &= ~PURGEBITS;
 966         mm->mmrover->attributes |= purge;
 967 }
 968
 969 //==========================================================================
 970
 971 /*
 972 =====================
 973 =
 974 = MM_SetLock
 975 =
 976 = Locks / unlocks the block
 977 =
 978 =====================
 979 */
 980
 981 void MM_SetLock(memptr *baseptr, boolean locked, mminfo_t *mm)
 982 {
 983         mmblocktype huge *start;
 984
 985         start = mm->mmrover;
 986
 987         do
 988         {
 989                 if(mm->mmrover->useptr == baseptr)
 990                         break;
 991
 992                 mm->mmrover = mm->mmrover->next;
 993
 994                 if(!mm->mmrover)
 995                         mm->mmrover = mm->mmhead;
 996                 else if(mm->mmrover == start)
 997                 {
 998                         printf("MM_SetLock: Block not found!");
 999                         return;
1000                 }
1001
1002         } while(1);
1003
1004         mm->mmrover->attributes &= ~LOCKBIT;
1005         mm->mmrover->attributes |= locked*LOCKBIT;
1006 }
1007
1008 //==========================================================================
1009
1010 /*
1011 =====================
1012 =
1013 = MM_SortMem
1014 =
1015 = Throws out all purgable stuff and compresses movable blocks
1016 =
1017 =====================
1018 */
1019
1020 void MM_SortMem(mminfo_t *mm)
1021 {
1022         mmblocktype huge *scan,huge *last,huge *next;
1023         unsigned        start,length,source,dest,oldborder;
1024         int                     playing;
1025
1026         //
1027         // lock down a currently playing sound
1028         //
1029 /*++++  playing = SD_SoundPlaying ();
1030         if(playing)
1031         {
1032                 switch (SoundMode)
1033                 {
1034                 case sdm_PC:
1035                         playing += STARTPCSOUNDS;
1036                         break;
1037                 case sdm_AdLib:
1038                         playing += STARTADLIBSOUNDS;
1039                         break;
1040                 }
1041                 MM_SetLock(&(memptr)audiosegs[playing],true);
1042         }
1043
1044
1045         SD_StopSound();*/
1046 //      oldborder = bordercolor;
1047 //      VW_ColorBorder (15);
1048
1049         if(beforesort)
1050                 beforesort();
1051
1052         scan = mm->mmhead;
1053
1054         last = NULL;            // shut up compiler warning
1055
1056         while(scan)
1057         {
1058                 if(scan->attributes & LOCKBIT)
1059                 {
1060                 //
1061                 // block is locked, so try to pile later blocks right after it
1062                 //
1063                         start = scan->start + scan->length;
1064                 }
1065                 else
1066                 {
1067                         if(scan->attributes & PURGEBITS)
1068                         {
1069                         //
1070                         // throw out the purgable block
1071                         //
1072                                 next = scan->next;
1073                                 MM_FreeBlock(scan, mm);
1074                                 last->next = next;
1075                                 scan = next;
1076                                 continue;
1077                         }
1078                         else
1079                         {
1080                         //
1081                         // push the non purgable block on top of the last moved block
1082                         //
1083                                 if(scan->start != start)
1084                                 {
1085                                         length = scan->length;
1086                                         source = scan->start;
1087                                         dest = start;
1088                                         while(length > 0xf00)
1089                                         {
1090                                                 movedata(source,0,dest,0,0xf00*16);
1091                                                 length -= 0xf00;
1092                                                 source += 0xf00;
1093                                                 dest += 0xf00;
1094                                         }
1095                                         movedata(source,0,dest,0,length*16);
1096
1097                                         scan->start = start;
1098                                         *(unsigned *)scan->useptr = start;
1099                                 }
1100                                 start = scan->start + scan->length;
1101                         }
1102                 }
1103
1104                 last = scan;
1105                 scan = scan->next;              // go to next block
1106         }
1107
1108         mm->mmrover = mm->mmhead;
1109
1110         if(aftersort)
1111                 aftersort();
1112
1113 //      VW_ColorBorder (oldborder);
1114
1115 /*++++  if(playing)
1116                 MM_SetLock(&(memptr)audiosegs[playing],false);*/
1117 }
1118
1119
1120 //==========================================================================
1121
1122 //****#if 0
1123 /*
1124 =====================
1125 =
1126 = MM_ShowMemory
1127 =
1128 =====================
1129 */
1130
1131 void MM_ShowMemory(/*page_t *page, */mminfo_t *mm)
1132 {
1133         mmblocktype huge *scan;
1134         word color,temp;
1135         long    end,owner;
1136         word chx,chy;
1137         byte    scratch[160],str[16];
1138
1139 //****  VW_SetDefaultColors();
1140 //****  VW_SetLineWidth(40);
1141 //++++mh        temp = bufferofs;
1142 //++++mh        bufferofs = 0;
1143 //****  VW_SetScreen (0,0);
1144
1145         scan = mm->mmhead;
1146
1147         end = -1;
1148
1149 CA_OpenDebug ();
1150
1151         chx=0;
1152         chy=0;
1153
1154         while(scan)
1155         {
1156                 if(scan->attributes & PURGEBITS)
1157                         color = 5;              // dark purple = purgable
1158                 else
1159                         color = 9;              // medium blue = non purgable
1160                 if(scan->attributes & LOCKBIT)
1161                         color = 12;             // red = locked
1162                 if(scan->start<=end)
1163                 {
1164                         //printf(");
1165                         write(debughandle,"\nMM_ShowMemory: Memory block order currupted!\n",strlen("\nMM_ShowMemory: Memory block order currupted!\n"));
1166                         //modexprint(&page, chx, chy, 1, 0, 24, "\nMM_ShowMemory: Memory block order currupted!\n");
1167                         return;
1168                 }
1169                 end = scan->start+scan->length-1;
1170                 chy = scan->start/320;
1171                 chx = scan->start%320;
1172                                 //modexhlin(page, scan->start, (unsigned)end, chy, color);
1173                                 //for(chx=scan->start;chx+4>=(word)end;chx+=4)
1174                                 //{
1175 //++++                                  modexClearRegion(page, chx, chy, 4, 4, color);
1176                                 //}
1177
1178 //++++          VW_Hlin(scan->start,(unsigned)end,0,color);
1179
1180 //++++          VW_Plot(scan->start,0,15);
1181 //++++                          modexClearRegion(page, chx, chy, 4, 4, 15);
1182                 if(scan->next->start > end+1)
1183 //++++                  VW_Hlin(end+1,scan->next->start,0,0);   // black = free
1184                         //for(chx=scan->next->start;chx+4>=(word)end+1;chx+=4)
1185                         //{
1186 //++++                          chx+=scan->next->start;
1187 //++++                          modexClearRegion(page, chx, chy, 4, 4, 2);
1188                         //}
1189                                         //modexhlin(page, end+1,scan->next->start, chy, 0);
1190
1191 /*
1192                 end = scan->length-1;
1193                 y = scan->start/320;
1194                 x = scan->start%320;
1195                 VW_Hlin(x,x+end,y,color);
1196                 VW_Plot(x,y,15);
1197                 if (scan->next && scan->next->start > end+1)
1198                         VW_Hlin(x+end+1,x+(scan->next->start-scan->start),y,0); // black = free
1199 */
1200
1201 //****#if 0
1202 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
1203 strcpy(scratch,"Seg:");
1204 ultoa (scan->start,str,16);
1205 strcat (scratch,str);
1206 strcat (scratch,"\tSize:");
1207 ultoa ((dword)scan->length,str,10);
1208 strcat (scratch,str);
1209 strcat (scratch,"\tOwner:0x");
1210 owner = (unsigned)scan->useptr;
1211 ultoa (owner,str,16);
1212 strcat (scratch,str);
1213 strcat (scratch,"\n");
1214 write(debughandle,scratch,strlen(scratch));
1215 //modexprint(page, chx, chy, 1, 0, 24, &scratch);
1216 //++++chy+=4;
1217 //fprintf(stdout, "%s", scratch);
1218 //****#endif
1219
1220                 scan = scan->next;
1221         }
1222
1223 CA_CloseDebug ();
1224
1225 //++++mh        IN_Ack();
1226 //****  VW_SetLineWidth(64);
1227 //++++mh        bufferofs = temp;
1228 }
1229 //****#endif
1230
1231 //==========================================================================
1232
1233 /*
1234 =====================
1235 =
1236 = MM_DumpData
1237 =
1238 =====================
1239 */
1240
1241 void MM_DumpData(mminfo_t *mm)
1242 {
1243         mmblocktype far *scan,far *best;
1244         long    lowest,oldlowest;
1245         word    owner;
1246         byte    lock,purge;
1247         FILE    *dumpfile;
1248
1249
1250         //++++free(mm->nearheap);
1251         dumpfile = fopen ("mmdump.16","w");
1252         if (!dumpfile){
1253                 printf("MM_DumpData: Couldn't open MMDUMP.16!\n");
1254                 return;
1255         }
1256
1257         lowest = -1;
1258         do
1259         {
1260                 oldlowest = lowest;
1261                 lowest = 0xffff;
1262
1263                 scan = mm->mmhead;
1264                 while (scan)
1265                 {
1266                         owner = (word)scan->useptr;
1267
1268                         if (owner && owner<lowest && owner > oldlowest)
1269                         {
1270                                 best = scan;
1271                                 lowest = owner;
1272                         }
1273
1274                         scan = scan->next;
1275                 }
1276
1277                 if (lowest != 0xffff)
1278                 {
1279                         if (best->attributes & PURGEBITS)
1280                                 purge = 'P';
1281                         else
1282                                 purge = '-';
1283                         if (best->attributes & LOCKBIT)
1284                                 lock = 'L';
1285                         else
1286                                 lock = '-';
1287                         fprintf (dumpfile,"0x%p (%c%c) = %u\n"
1288                         ,(word)lowest,lock,purge,best->length);
1289                 }
1290
1291         } while (lowest != 0xffff);
1292
1293         fclose(dumpfile);
1294         printf("MMDUMP.16 created.\n");
1295 }
1296
1297 //==========================================================================
1298
1299
1300 /*
1301 ======================
1302 =
1303 = MM_UnusedMemory
1304 =
1305 = Returns the total free space without purging
1306 =
1307 ======================
1308 */
1309
1310 dword MM_UnusedMemory(mminfo_t *mm)
1311 {
1312         dword free;
1313         mmblocktype huge *scan;
1314
1315         free = 0;
1316         scan = mm->mmhead;
1317
1318         while(scan->next)
1319         {
1320                 free += scan->next->start - (scan->start + scan->length);
1321                 scan = scan->next;
1322         }
1323
1324 //      return free*16l;
1325         return free;
1326 }
1327
1328 //==========================================================================
1329
1330
1331 /*
1332 ======================
1333 =
1334 = MM_TotalFree
1335 =
1336 = Returns the total free space with purging
1337 =
1338 ======================
1339 */
1340
1341 dword MM_TotalFree(mminfo_t *mm)
1342 {
1343         dword free;
1344         mmblocktype huge *scan;
1345
1346         free = 0;
1347         scan = mm->mmhead;
1348
1349         while(scan->next)
1350         {
1351                 if((scan->attributes&PURGEBITS) && !(scan->attributes&LOCKBIT))
1352                         free += scan->length;
1353                 free += scan->next->start - (scan->start + scan->length);
1354                 scan = scan->next;
1355         }
1356
1357 //      return free*16l;
1358         return free;
1359 }
1360
1361 //==========================================================================
1362
1363 /*
1364 =====================
1365 =
1366 = MM_Report
1367 =
1368 =====================
1369 */
1370
1371 void MM_Report(/*page_t *page, */mminfo_t *mm, mminfotype *mmi)
1372 {
1373         if(MML_CheckForEMS())
1374         {
1375                 printf("EMM v%x.%x available\n", mm->EMSVer>>4,mm->EMSVer&0x0F);
1376                 printf("totalEMSpages=%u\n", mm->totalEMSpages);
1377                 printf("freeEMSpages=%u\n", mm->freeEMSpages);
1378                 printf("EMSpageframe=%x\n", mm->EMSpageframe);
1379         }
1380         if(MML_CheckForXMS(mm)) printf("XMSaddr=%X\n", *XMSaddr);
1381         printf("near=%lu\n", mmi->nearheap);
1382         printf("far=%lu\n", mmi->farheap);
1383         printf("EMSmem=%lu\n", mmi->EMSmem);
1384         printf("XMSmem=%lu\n", mmi->XMSmem);
1385         printf("mainmem=%lu\n", mmi->mainmem);
1386         printf("UnusedMemory=%lu\n", MM_UnusedMemory(mm));
1387         printf("TotalFree=%lu\n", MM_TotalFree(mm));
1388         //mmi->nearheap+mmi->farheap+
1389         printf("TotalUsed=%lu\n", mmi->mainmem+mmi->EMSmem+mmi->XMSmem);//+);
1390 //      printf("\n");
1391 //      printf("UnusedMemory=%lu kb\n", MM_UnusedMemory()/10248);
1392 //      printf("TotalFree=%lu kb\n", MM_TotalFree()/10248);
1393 }
1394
1395 //==========================================================================
1396
1397 /*
1398 =====================
1399 =
1400 = MM_EMSerr
1401 =
1402 =====================
1403 */
1404
1405 void MM_EMSerr(byte *stri, byte err)
1406 {
1407         //Returns a text string describing the error code in EMS.Error.
1408         switch(err)
1409         {
1410                 case 0x0:
1411                         strcat(stri, "successful");
1412                 break;
1413                 case 0x80:
1414                         strcat(stri, "internal error");
1415                 break;
1416                 case 0x81:
1417                         strcat(stri, "hardware malfunction");
1418                 break;
1419                 case 0x82:
1420                         strcat(stri, "busy .. retry later");
1421                 break;
1422                 case 0x83:
1423                         strcat(stri, "invalid handle");
1424                 break;
1425                 case 0x84:
1426                         strcat(stri, "undefined function requested by application");
1427                 break;
1428                 case 0x85:
1429                         strcat(stri, "no more handles available");
1430                 break;
1431                 case 0x86:
1432                         strcat(stri, "error in save or restore of mapping context");
1433                 break;
1434                 case 0x87:
1435                         strcat(stri, "insufficient memory pages in system");
1436                 break;
1437                 case 0x88:
1438                         strcat(stri, "insufficient memory pages available");
1439                 break;
1440                 case 0x89:
1441                         strcat(stri, "zero pages requested");
1442                 break;
1443                 case 0x8A:
1444                         strcat(stri, "invalid logical page number encountered");
1445                 break;
1446                 case 0x8B:
1447                         strcat(stri, "invalid physical page number encountered");
1448                 break;
1449                 case 0x8C:
1450                         strcat(stri, "page-mapping hardware state save area is full");
1451                 break;
1452                 case 0x8D:
1453                         strcat(stri, "save of mapping context failed");
1454                 break;
1455                 case 0x8E:
1456                         strcat(stri, "restore of mapping context failed");
1457                 break;
1458                 case 0x8F:
1459                         strcat(stri, "undefined subfunction");
1460                 break;
1461                 case 0x90:
1462                         strcat(stri, "undefined attribute type");
1463                 break;
1464                 case 0x91:
1465                         strcat(stri, "feature not supported");
1466                 break;
1467                 case 0x92:
1468                         strcat(stri, "successful, but a portion of the source region has been overwritten");
1469                 break;
1470                 case 0x93:
1471                         strcat(stri, "length of source or destination region exceeds length of region allocated to either source or destination handle");
1472                 break;
1473                 case 0x94:
1474                         strcat(stri, "conventional and expanded memory regions overlap");
1475                 break;
1476                 case 0x95:
1477                         strcat(stri, "offset within logical page exceeds size of logical page");
1478                 break;
1479                 case 0x96:
1480                         strcat(stri, "region length exceeds 1 MB");
1481                 break;
1482                 case 0x97:
1483                         strcat(stri, "source and destination EMS regions have same handle and overlap");
1484                 break;
1485                 case 0x98:
1486                         strcat(stri, "memory source or destination type undefined");
1487                 break;
1488                 case 0x9A:
1489                         strcat(stri, "specified alternate map register or DMA register set not supported");
1490                 break;
1491                 case 0x9B:
1492                         strcat(stri, "all alternate map register or DMA register sets currently allocated");
1493                 break;
1494                 case 0x9C:
1495                         strcat(stri, "alternate map register or DMA register sets not supported");
1496                 break;
1497                 case 0x9D:
1498                         strcat(stri, "undefined or unallocated alternate map register or DMA register set");
1499                 break;
1500                 case 0x9E:
1501                         strcat(stri, "dedicated DMA channels not supported");
1502                 break;
1503                 case 0x9F:
1504                         strcat(stri, "specified dedicated DMA channel not supported");
1505                 break;
1506                 case 0xA0:
1507                         strcat(stri, "no such handle name");
1508                 break;
1509                 case 0xA1:
1510                         strcat(stri, "a handle found had no name, or duplicate handle name");
1511                 break;
1512                 case 0xA2:
1513                         strcat(stri, "attempted to wrap around 1M conventional address space");
1514                 break;
1515                 case 0xA3:
1516                         strcat(stri, "source array corrupted");
1517                 break;
1518                 case 0xA4:
1519                         strcat(stri, "operating system denied access");
1520                 break;
1521                 default:
1522                         strcat(stri, "undefined error");
1523         }
1524 }
1525
1526 //==========================================================================
1527
1528 /*
1529 =====================
1530 =
1531 = MM_BombOnError
1532 =
1533 =====================
1534 */
1535
1536 void MM_BombOnError(boolean bomb, mminfo_t *mm)
1537 {
1538         mm->bombonerror = bomb;
1539 }
1540
1541 void MM_GetNewBlock(mminfo_t *mm)
1542 {
1543         if(!mm->mmfree)
1544                 MML_ClearBlock(mm);
1545         mm->mmnew=mm->mmfree;
1546         mm->mmfree=mm->mmfree->next;
1547         /*if(!(mm->mmnew=mm->mmfree))
1548         {
1549                 printf("MM_GETNEWBLOCK: No free blocks!");
1550                 return;
1551         }
1552         mm->mmfree=mm->mmfree->next;*/
1553 }
1554
1555 void MM_FreeBlock(mmblocktype *x, mminfo_t *mm)
1556 {
1557         x->useptr=NULL;
1558         x->next=mm->mmfree;
1559         mm->mmfree=x;
1560 }
1561
1562 void MM_seguin(void)
1563 {
1564         __asm
1565         {
1566                 push    ds
1567                 mov     ax,ds
1568                 inc             ax
1569                 mov     ds,ax
1570         }
1571 }
1572
1573 void MM_segude(void)
1574 {
1575         __asm
1576         {
1577                 pop ds
1578         }
1579 }
1580
1581 /*
1582 pull data from far and put it into ds var
1583 mov ax,es:si
1584 mov x,ax
1585 */
1586 /*
1587 ss stack segment
1588 sp top of stack
1589 bp bottem of stack
1590 */