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Microsoft MS-DOS 6.00 (Compressed)

In March 1993, Microsoft released MS-DOS 6.00, the next major release of MS-DOS after 5.00 shipped in June 1991.

In addition to several new full-screen utilities, like DEFRAG to defragment your hard disk (licensed from Symantec), MSBACKUP to efficiently backup your hard disk (also licensed from Symantec), and MSAV to check for viruses (licensed from Central Point Software), there were a number of new command-line programs, such as CHOICE, DELTREE, MOVE, MSCDEX, and SMARTDRV.

But the biggest addition to MS-DOS 6.00 was a new feature called DoubleSpace (dubbed “MagicDrive” internally) that automatically compressed everything on your hard disk, providing up to “double” the amount of effective disk space – or more, or less, depending on how compressible your files were overall.

See this blog post for more information – and some personal trivia – regarding MS-DOS 6.00.

[PCjs Machine "compaq386-msdos600"]

Waiting for machine "compaq386-msdos600" to load....

NOTE: The machine above is configured with a 20Mb hard disk, with MS-DOS 6.00 preinstalled, and the disk has already been compressed. The same machine with an uncompressed disk is also available.

If you’re interested in stepping through the actual DoubleSpace compression or decompression code using the PCjs Debugger, here are some handy breakpoints to get you started:

The compression breakpoint is at the start of the compressor, whereas the decompression breakpoint is where a signature word (DS) is being checked before entering the bowels of the decompressor.

Directory listings of the four 1.2M and three 1.44M distribution diskettes are provided below.

Directory of MS-DOS 6.00 (1.2M Disk 1)

 Volume in drive A is DISK      1
 Directory of A:\

IO       SYS*    40470   3-10-93   6:00a
MSDOS    SYS*    38138   3-10-93   6:00a
ANSI     SY_      6260   3-10-93   6:00a
ATTRIB   EXE     11165   3-10-93   6:00a
AUTOEXEC BAT        36   3-10-93   6:00a
CHKDSK   EXE     12907   3-10-93   6:00a
COMMAND  COM     52925   3-10-93   6:00a
CONFIG   SYS        13   3-10-93   6:00a
COUNTRY  SYS     17066   3-10-93   6:00a
DBLSPACE BIN     51214   3-10-93   6:00a
DEBUG    EXE     15715   3-10-93   6:00a
DOSSETUP INI      3735   3-10-93   6:00a
EDIT     COM       413   3-10-93   6:00a
EXPAND   EXE     16129   3-10-93   6:00a
FDISK    EXE     29333   3-10-93   6:00a
FORMAT   COM     22717   3-10-93   6:00a
KEYB     COM     14983   3-10-93   6:00a
KEYBOARD SYS     34694   3-10-93   6:00a
MORE     COM      2546   3-10-93   6:00a
MSD      EXE    158470   3-10-93   6:00a
NETWORKS TXT     20463   3-10-93   6:00a
NLSFUNC  EXE      7036   3-10-93   6:00a
PACKING  LST      6929   3-10-93   6:00a
QBASIC   EXE    194309   3-10-93   6:00a
README   TXT     44990   3-10-93   6:00a
RESTORE  EX_     23328   3-10-93   6:00a
SETUP    EXE     71974   3-10-93   6:00a
SETUP    MSG      1290   3-10-93   6:00a
SYS      COM      9379   3-10-93   6:00a
UNFORMAT COM     12738   3-10-93   6:00a
       30 file(s)     921365 bytes
                      284672 bytes free

Directory of MS-DOS 6.00 (1.2M Disk 2)

 Volume in drive A is DISK      2
 Directory of A:\

8514     VI_      6421   3-10-93   6:00a
APPEND   EX_      7462   3-10-93   6:00a
CGA      GR_      1617   3-10-93   6:00a
CGA      IN_      2775   3-10-93   6:00a
CGA      VI_      6131   3-10-93   6:00a
CHOICE   COM      1754   3-10-93   6:00a
DEFRAG   EXE     75033   3-10-93   6:00a
DEFRAG   HL_      4284   3-10-93   6:00a
DELTREE  EX_      7253   3-10-93   6:00a
DISKCOMP CO_      6657   3-10-93   6:00a
DISKCOPY CO_      7382   3-10-93   6:00a
DISPLAY  SY_      9796   3-10-93   6:00a
DOSHELP  HL_      2492   3-10-93   6:00a
DOSKEY   CO_      4217   3-10-93   6:00a
DOSSHELL CO_      1907   3-10-93   6:00a
DOSSHELL EX_    142511   3-10-93   6:00a
DOSSWAP  EX_     13498   3-10-93   6:00a
DRIVER   SY_      4027   3-10-93   6:00a
EDIT     HL_     15709   3-10-93   6:00a
EGA      CP_     18186   3-10-93   6:00a
EGA      GR_      2466   3-10-93   6:00a
EGA      IN_      2776   3-10-93   6:00a
EGA      SY_      3684   3-10-93   6:00a
EGA      VI_      6160   3-10-93   6:00a
EGAMONO  GR_      2318   3-10-93   6:00a
FASTHELP EX_      7539   3-10-93   6:00a
FASTOPEN EX_      7783   3-10-93   6:00a
FC       EX_     12065   3-10-93   6:00a
FIND     EX_      4877   3-10-93   6:00a
GRAPHICS CO_     11327   3-10-93   6:00a
GRAPHICS PR_      3883   3-10-93   6:00a
HELP     COM       413   3-10-93   6:00a
HELP     HL_    263819   3-10-93   6:00a
HERC     GR_      1636   3-10-93   6:00a
HERC     VI_      6271   3-10-93   6:00a
HIMEM    SY_      8497   3-10-93   6:00a
LABEL    EX_      6176   3-10-93   6:00a
LOADFIX  CO_       649   3-10-93   6:00a
MEM      EX_     19147   3-10-93   6:00a
MODE     CO_     14849   3-10-93   6:00a
MONO     GR_       296   3-10-93   6:00a
MONO     IN_      2451   3-10-93   6:00a
MOVE     EX_     11659   3-10-93   6:00a
POWER    EX_      5549   3-10-93   6:00a
PRINT    EX_      9614   3-10-93   6:00a
QBASIC   HL_    113105   3-10-93   6:00a
RAMDRIVE SY_      3282   3-10-93   6:00a
REPLACE  EX_     12800   3-10-93   6:00a
SETVER   EX_      6635   3-10-93   6:00a
SHARE    EX_      8116   3-10-93   6:00a
SMARTDRV EX_     13793   3-10-93   6:00a
SMARTMON EX_     13747   3-10-93   6:00a
SMARTMON HL_      7319   3-10-93   6:00a
SORT     EX_      4355   3-10-93   6:00a
SUBST    EX_     12710   3-10-93   6:00a
TREE     CO_      4753   3-10-93   6:00a
VGA      GR_      3198   3-10-93   6:00a
VGA      VI_      6355   3-10-93   6:00a
VGAMONO  GR_      3214   3-10-93   6:00a
WINA20   38_      2661   3-10-93   6:00a
XCOPY    EX_     10368   3-10-93   6:00a
       61 file(s)     981427 bytes
                      216576 bytes free

Directory of MS-DOS 6.00 (1.2M Disk 3)

 Volume in drive A is DISK      3
 Directory of A:\

CHKSTATE SY_     16770   3-10-93   6:00a
MEMMAKER HL_      5980   3-10-93   6:00a
MEMMAKER IN_       800   3-10-93   6:00a
MSBACKDB OVL     63098   3-10-93   6:00a
MSBACKDR OVL     66906   3-10-93   6:00a
MSBACKFB OVL     69066   3-10-93   6:00a
MSBACKFR OVL     72474   3-10-93   6:00a
MSBACKUP EX_      2487   3-10-93   6:00a
MSBACKUP HL_    112396   3-10-93   6:00a
MSBACKUP OVL    133952   3-10-93   6:00a
MSBCONFG HL_     18549   3-10-93   6:00a
MSBCONFG OVL     47210   3-10-93   6:00a
MWBACKF  DL_      6956   3-10-93   6:00a
MWBACKR  DL_     30277   3-10-93   6:00a
MWBACKUP EX_    159138   3-10-93   6:00a
MWBACKUP HL_    141281   3-10-93   6:00a
MWGRAFIC DL_     18094   3-10-93   6:00a
MWUNDEL  EX_     65900   3-10-93   6:00a
MWUNDEL  HL_     17458   3-10-93   6:00a
UNDELETE EXE     26420   3-10-93   6:00a
VFINTD   38_      1289   3-10-93   6:00a
WNTOOLS  GR_      1071   3-10-93   6:00a
       22 file(s)    1077572 bytes
                      131072 bytes free

Directory of MS-DOS 6.00 (1.2M Disk 4)

 Volume in drive A is DISK      4
 Directory of A:\

DBLSPACE EX_    170947   3-10-93   6:00a
DBLSPACE HL_     22203   3-10-93   6:00a
DBLSPACE IN_      1060   3-10-93   6:00a
DBLSPACE SYS       339   3-10-93   6:00a
DBLWIN   HL_      4205   3-10-93   6:00a
DOSSHELL HL_     48773   3-10-93   6:00a
EMM386   EX_     48725   3-10-93   6:00a
INTERLNK EX_     10720   3-10-93   6:00a
INTERSVR EX_     26343   3-10-93   6:00a
MEMMAKER EXE    118660   3-10-93   6:00a
MONOUMB  38_       950   3-10-93   6:00a
MSAV     EXE    172198   3-10-93   6:00a
MSAV     HL_     12230   3-10-93   6:00a
MSAVHELP OV_     17796   3-10-93   6:00a
MSAVIRUS LS_     11473   3-10-93   6:00a
MSCDEX   EXE     25377   3-10-93   6:00a
MSTOOLS  DL_      8376   3-10-93   6:00a
MWAV     EX_     65629   3-10-93   6:00a
MWAV     HL_     12070   3-10-93   6:00a
MWAVABSI DL_     23085   3-10-93   6:00a
MWAVDLG  DL_     10232   3-10-93   6:00a
MWAVDOSL DL_     19702   3-10-93   6:00a
MWAVDRVL DL_      4219   3-10-93   6:00a
MWAVMGR  DL_      9569   3-10-93   6:00a
MWAVSCAN DL_     70797   3-10-93   6:00a
MWAVSOS  DL_      3983   3-10-93   6:00a
MWAVTSR  EX_      8445   3-10-93   6:00a
SIZER    EX_      4136   3-10-93   6:00a
VSAFE    CO_     33046   3-10-93   6:00a
COUNTRY  IC_      3266   3-10-93   6:00a
EGA      IC_     22791   3-10-93   6:00a
KEYBOARD IC_      8243   3-10-93   6:00a
       32 file(s)     999588 bytes
                      205824 bytes free

Directory of MS-DOS 6.00 (1.44M Disk 1)

 Volume in drive A is DISK      1
 Directory of A:\

IO       SYS*    40470   3-10-93   6:00a
MSDOS    SYS*    38138   3-10-93   6:00a
8514     VI_      6421   3-10-93   6:00a
ANSI     SY_      6260   3-10-93   6:00a
ATTRIB   EXE     11165   3-10-93   6:00a
AUTOEXEC BAT        36   3-10-93   6:00a
CGA      GR_      1617   3-10-93   6:00a
CGA      IN_      2775   3-10-93   6:00a
CGA      VI_      6131   3-10-93   6:00a
CHKDSK   EXE     12907   3-10-93   6:00a
CHOICE   COM      1754   3-10-93   6:00a
COMMAND  COM     52925   3-10-93   6:00a
CONFIG   SYS        13   3-10-93   6:00a
COUNTRY  SYS     17066   3-10-93   6:00a
DBLSPACE BIN     51214   3-10-93   6:00a
DEBUG    EXE     15715   3-10-93   6:00a
DEFRAG   EXE     75033   3-10-93   6:00a
DEFRAG   HL_      4284   3-10-93   6:00a
DELTREE  EX_      7253   3-10-93   6:00a
DOSSETUP INI      3723   3-10-93   6:00a
DOSSWAP  EX_     13498   3-10-93   6:00a
EDIT     COM       413   3-10-93   6:00a
EGA      CP_     18186   3-10-93   6:00a
EGA      GR_      2466   3-10-93   6:00a
EGA      IN_      2776   3-10-93   6:00a
EGA      SY_      3684   3-10-93   6:00a
EGA      VI_      6160   3-10-93   6:00a
EGAMONO  GR_      2318   3-10-93   6:00a
EXPAND   EXE     16129   3-10-93   6:00a
FDISK    EXE     29333   3-10-93   6:00a
FORMAT   COM     22717   3-10-93   6:00a
HERC     GR_      1636   3-10-93   6:00a
HERC     VI_      6271   3-10-93   6:00a
HIMEM    SY_      8497   3-10-93   6:00a
KEYB     COM     14983   3-10-93   6:00a
KEYBOARD SYS     34694   3-10-93   6:00a
MEM      EX_     19147   3-10-93   6:00a
MONO     GR_       296   3-10-93   6:00a
MONO     IN_      2451   3-10-93   6:00a
MORE     COM      2546   3-10-93   6:00a
MOVE     EX_     11659   3-10-93   6:00a
MSD      EXE    158470   3-10-93   6:00a
README   TXT     44990   3-10-93   6:00a
NETWORKS TXT     20463   3-10-93   6:00a
NLSFUNC  EXE      7036   3-10-93   6:00a
PACKING  LST      6899   3-10-93   6:00a
QBASIC   EXE    194309   3-10-93   6:00a
RAMDRIVE SY_      3282   3-10-93   6:00a
RESTORE  EX_     23328   3-10-93   6:00a
SETUP    EXE     71974   3-10-93   6:00a
SETUP    MSG      1290   3-10-93   6:00a
SMARTDRV EX_     13793   3-10-93   6:00a
SYS      COM      9379   3-10-93   6:00a
UNFORMAT COM     12738   3-10-93   6:00a
VGA      GR_      3198   3-10-93   6:00a
VGA      VI_      6355   3-10-93   6:00a
VGAMONO  GR_      3214   3-10-93   6:00a
WINA20   38_      2661   3-10-93   6:00a
XCOPY    EX_     10368   3-10-93   6:00a
       59 file(s)    1168507 bytes
                      272896 bytes free

Directory of MS-DOS 6.00 (1.44M Disk 2)

 Volume in drive A is DISK      2
 Directory of A:\

APPEND   EX_      7462   3-10-93   6:00a
DISKCOMP CO_      6657   3-10-93   6:00a
DISKCOPY CO_      7382   3-10-93   6:00a
DISPLAY  SY_      9796   3-10-93   6:00a
DOSHELP  HL_      2492   3-10-93   6:00a
DOSKEY   CO_      4217   3-10-93   6:00a
DOSSHELL CO_      1907   3-10-93   6:00a
DOSSHELL EX_    142511   3-10-93   6:00a
DRIVER   SY_      4027   3-10-93   6:00a
EDIT     HL_     15709   3-10-93   6:00a
FASTHELP EX_      7539   3-10-93   6:00a
FASTOPEN EX_      7783   3-10-93   6:00a
FC       EX_     12065   3-10-93   6:00a
FIND     EX_      4877   3-10-93   6:00a
GRAPHICS CO_     11327   3-10-93   6:00a
GRAPHICS PR_      3883   3-10-93   6:00a
HELP     COM       413   3-10-93   6:00a
HELP     HL_    263819   3-10-93   6:00a
LABEL    EX_      6176   3-10-93   6:00a
LOADFIX  CO_       649   3-10-93   6:00a
MODE     CO_     14849   3-10-93   6:00a
MSBACKFB OVL     69066   3-10-93   6:00a
MSBACKFR OVL     72474   3-10-93   6:00a
MSBACKUP EX_      2487   3-10-93   6:00a
MSBACKUP OVL    133952   3-10-93   6:00a
MWBACKF  DL_      6956   3-10-93   6:00a
MWBACKR  DL_     30277   3-10-93   6:00a
MWBACKUP EX_    159138   3-10-93   6:00a
MWBACKUP HL_    141281   3-10-93   6:00a
POWER    EX_      5549   3-10-93   6:00a
PRINT    EX_      9614   3-10-93   6:00a
QBASIC   HL_    113105   3-10-93   6:00a
REPLACE  EX_     12800   3-10-93   6:00a
SETVER   EX_      6635   3-10-93   6:00a
SHARE    EX_      8116   3-10-93   6:00a
SMARTMON EX_     13747   3-10-93   6:00a
SMARTMON HL_      7319   3-10-93   6:00a
SORT     EX_      4355   3-10-93   6:00a
SUBST    EX_     12710   3-10-93   6:00a
TREE     CO_      4753   3-10-93   6:00a
VFINTD   38_      1289   3-10-93   6:00a
COUNTRY  IC_      3266   3-10-93   6:00a
EGA      IC_     22791   3-10-93   6:00a
KEYBOARD IC_      8243   3-10-93   6:00a
       44 file(s)    1385463 bytes
                       61952 bytes free

Directory of MS-DOS 6.00 (1.44M Disk 3)

 Volume in drive A is DISK      3
 Directory of A:\

CHKSTATE SY_     16770   3-10-93   6:00a
DBLSPACE EX_    170947   3-10-93   6:00a
DBLSPACE HL_     22203   3-10-93   6:00a
DBLSPACE IN_      1060   3-10-93   6:00a
DBLSPACE SYS       339   3-10-93   6:00a
DBLWIN   HL_      4205   3-10-93   6:00a
DOSSHELL HL_     48773   3-10-93   6:00a
EMM386   EX_     48725   3-10-93   6:00a
INTERLNK EX_     10720   3-10-93   6:00a
INTERSVR EX_     26343   3-10-93   6:00a
MEMMAKER EXE    118660   3-10-93   6:00a
MEMMAKER HL_      5980   3-10-93   6:00a
MEMMAKER IN_       800   3-10-93   6:00a
MONOUMB  38_       950   3-10-93   6:00a
MSAV     EXE    172198   3-10-93   6:00a
MSAV     HL_     12230   3-10-93   6:00a
MSAVHELP OV_     17796   3-10-93   6:00a
MSAVIRUS LS_     11473   3-10-93   6:00a
MSBACKDB OVL     63098   3-10-93   6:00a
MSBACKDR OVL     66906   3-10-93   6:00a
MSBACKUP HL_    112396   3-10-93   6:00a
MSBCONFG HL_     18549   3-10-93   6:00a
MSBCONFG OVL     47210   3-10-93   6:00a
MSCDEX   EXE     25377   3-10-93   6:00a
MSTOOLS  DL_      8376   3-10-93   6:00a
MWAV     EX_     65629   3-10-93   6:00a
MWAV     HL_     12070   3-10-93   6:00a
MWAVABSI DL_     23085   3-10-93   6:00a
MWAVDLG  DL_     10232   3-10-93   6:00a
MWAVDOSL DL_     19702   3-10-93   6:00a
MWAVDRVL DL_      4219   3-10-93   6:00a
MWAVMGR  DL_      9569   3-10-93   6:00a
MWAVSCAN DL_     70797   3-10-93   6:00a
MWAVSOS  DL_      3983   3-10-93   6:00a
MWAVTSR  EX_      8445   3-10-93   6:00a
MWGRAFIC DL_     18094   3-10-93   6:00a
MWUNDEL  EX_     65900   3-10-93   6:00a
MWUNDEL  HL_     17458   3-10-93   6:00a
SIZER    EX_      4136   3-10-93   6:00a
UNDELETE EXE     26420   3-10-93   6:00a
VSAFE    CO_     33046   3-10-93   6:00a
WNTOOLS  GR_      1071   3-10-93   6:00a
       42 file(s)    1425940 bytes
                       20480 bytes free