IBM PC DOS 1.10 - Disk Contents

There were no changes since version 1.00. See our Disk Structure Table for 1.00.
IBM® Personal Computer™ DOS 1.10 was distributed on the same diskette type as the original: 160 KiB (163,840 bytes) divided into 40 tracks of only 8 SPT (sectors per track) for a total of 320 sectors on only 1 side of the diskette.

DISK CONTENTS

See our Tech Notes for DOS 1.00 on the difficulty of working with versions 1.10 and 1.00 of IBM®'s Personal Computer™ DOS; most notably, that you may not be able to use any other versions of DOS to copy files from these early diskettes unless the BIOS supports them. You can, however, still read the Directory under all later DOS versions [except in a Windows DOS-box] using the dir /a or dir /a:h commands (thus data about its two Hidden System files can be viewed when using much later versions of DOS):

 Volume in drive A has no label
 Directory of A:\

   File Name         Size    Allocated     Modified       Attrib

 IBMBIO   COM       1,920      2,048    05-07-82 12:00p     HS
 IBMDOS   COM       6,400      6,656    05-07-82 12:00p     HS
 COMMAND  COM       4,959      5,120    05-07-82 12:00p
 FORMAT   COM       3,816      4,096    05-07-82 12:00p
 CHKDSK   COM       1,720      2,048    05-07-82 12:00p
 SYS      COM         605      1,024    05-07-82 12:00p
 DISKCOPY COM       2,008      2,048    05-07-82 12:00p
 DISKCOMP COM       1,640      2,048    05-07-82 12:00p
 COMP     COM       1,649      2,048    05-07-82 12:00p
 EXE2BIN  EXE       1,280      1,536    05-07-82 12:00p
 MODE     COM       2,509      2,560    05-07-82 12:00p
 EDLIN    COM       2,392      2,560    05-07-82 12:00p
 DEBUG    COM       5,999      6,144    05-07-82 12:00p
 LINK     EXE      41,856     41,984    05-07-82 12:00p
 BASIC    COM      11,392     11,776    05-07-82 12:00p
 BASICA   COM      16,768     16,896    05-07-82 12:00p
 ART      BAS       1,920      2,048    05-07-82 12:00p
 SAMPLES  BAS       2,432      2,560    05-07-82 12:00p
 MORTGAGE BAS       6,272      6,656    05-07-82 12:00p
 COLORBAR BAS       1,536      1,536    05-07-82 12:00p
 CALENDAR BAS       3,840      4,096    05-07-82 12:00p
 MUSIC    BAS       8,704      8,704    05-07-82 12:00p
 DONKEY   BAS       3,584      3,584    05-07-82 12:00p
 CIRCLE   BAS       1,664      2,048    05-07-82 12:00p
 PIECHART BAS       2,304      2,560    05-07-82 12:00p
 SPACE    BAS       1,920      2,048    05-07-82 12:00p
 BALL     BAS       2,048      2,048    05-07-82 12:00p
 COMM     BAS       4,352      4,608    05-07-82 12:00p

       28 file(s)        147,489 bytes
         0 dir(s)        153,088 bytes allocated
                           7,168 bytes free
                         160,256 bytes total disk space,  95% in use

From our analysis of the disk's structure, we know there are only 160,256 bytes for the File area ("disk space" as seen in CHKDSK display above), because the Boot Record, FAT and Directory structures use 3,584 bytes of the disk's total capacity. We see above that 5% (or 7,168 bytes) of that space is left for user files. The diskette does in fact contain 163,840 bytes (160 KiB) of accessible data.

Location of Files on Diskette

By forcing a disk editor to use its "Physical" (vs. "Logical") view of the diskette, we were able to discover the physical location of each file as follows [Note: Most system utility programs, such as WinHex, will not recognize this diskette nor its image file, so we've added a column showing the Absolute Sector locations for each file. Absolute Sector = Cluster + 5 ]:

 Absolute Sector 3
 -----------------                                  Absolute
   Name   .Ext    Size    Date      Time    Cluster Sector(s)  A R S H D V

  IBMBIO   COM    1920   5-07-82  12:00 pm       2     7-10    - - S H - -
  IBMDOS   COM    6400   5-07-82  12:00 pm       6    11-23    - - S H - -
  COMMAND  COM    4959   5-07-82  12:00 pm      19    24-33
  FORMAT   COM    3816   5-07-82  12:00 pm      29    34-41
  CHKDSK   COM    1720   5-07-82  12:00 pm      37    42-45
  SYS      COM     605   5-07-82  12:00 pm      41    46-47
  DISKCOPY COM    2008   5-07-82  12:00 pm      43    48-51
  DISKCOMP COM    1640   5-07-82  12:00 pm      47    52-55
  COMP     COM    1649   5-07-82  12:00 pm      51    56-59
  EXE2BIN  EXE    1280   5-07-82  12:00 pm      55    60-62
  MODE     COM    2509   5-07-82  12:00 pm      58    63-67
  EDLIN    COM    2392   5-07-82  12:00 pm      63    68-72
  DEBUG    COM    5999   5-07-82  12:00 pm      68    73-84
  LINK     EXE   41856   5-07-82  12:00 pm      80    85-166
  BASIC    COM   11392   5-07-82  12:00 pm     162   167-189
  BASICA   COM   16768   5-07-82  12:00 pm     185   190-222

 Absolute Sector 4
 -----------------
  ART      BAS    1920   5-07-82  12:00 pm     218   223-226
  SAMPLES  BAS    2432   5-07-82  12:00 pm     222   227-231
  MORTGAGE BAS    6272   5-07-82  12:00 pm     227   232-244
  COLORBAR BAS    1536   5-07-82  12:00 pm     240   245-247
  CALENDAR BAS    3840   5-07-82  12:00 pm     243   248-255
  MUSIC    BAS    8704   5-07-82  12:00 pm     251   256-272
  DONKEY   BAS    3584   5-07-82  12:00 pm     268   273-279
  CIRCLE   BAS    1664   5-07-82  12:00 pm     275   280-283
  PIECHART BAS    2304   5-07-82  12:00 pm     279   284-288
  SPACE    BAS    1920   5-07-82  12:00 pm     284   289-292
  BALL     BAS    2048   5-07-82  12:00 pm     288   293-296
  COMM     BAS    4352   5-07-82  12:00 pm     292   297-305

  Last used cluster/sector on diskette:        300       305

  Unused sectors at end of diskette = 14
 (14 sectors x 512 bytes/sector = 7,168 bytes free space).

MD5 Sums for every File on the Diskette

For a complete introduction to using MD5 Sums (click here).
If you believe that one or more of the files on your DOS version 1.10 diskette have become corrupted, compare their MD5 sums with this listing:

On our DOS 1.00 Forensic Examination page, we've also included the MD5 hash for an image file of the whole diskette! Note: There's at least one other image file being passed around on the Net that differs from the one we copied directly from an actual DOS 1.10 diskette by only two bytes in the Directory area; but it takes only a 1-bit difference for the whole diskette to have a much different MD5 checksum! So even though every file above will match those from that other image file, the checksum (hash value) of that image will be completely different than our MD5 hash.

Disk Contents of the
IBM® Personal Computer™ DOS
Version 1.10 (1982)

Copyright © 2005 by Daniel B. Sedory

NOT to be reproduced in any form without Permission of the Author !

DISK STRUCTURE

DISK CONTENTS

Location of Files on Diskette

MD5 Sums for every File on the Diskette

Disk Contents of theIBM® Personal Computer™ DOS Version 1.10 (1982) Copyright © 2005 by Daniel B. Sedory NOT to be reproduced in any form without Permission of the Author !

DISK STRUCTURE

DISK CONTENTS

Location of Files on Diskette

MD5 Sums for every File on the Diskette

Disk Contents of the
IBM® Personal Computer™ DOS
Version 1.10 (1982)

Copyright © 2005 by Daniel B. Sedory

NOT to be reproduced in any form without Permission of the Author !