IBM
PC DOS 1.00 Index
MBR
and Boot Records IndexThe Starman's Realm Index
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.
See our Tech Notes 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.
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 location for the beginning of each file. Absolute Sector = Cluster + 5 ]:
Absolute Sector 3 ----------------- Absolute Name .Ext Size Date Time Cluster Sector A R S H D V IBMBIO COM 1920 5-07-82 12:00 pm 2 7 - - S H - - IBMDOS COM 6400 5-07-82 12:00 pm 6 11 - - S H - - COMMAND COM 4959 5-07-82 12:00 pm 19 24 FORMAT COM 3816 5-07-82 12:00 pm 29 34 CHKDSK COM 1720 5-07-82 12:00 pm 37 42 SYS COM 605 5-07-82 12:00 pm 41 46 DISKCOPY COM 2008 5-07-82 12:00 pm 43 48 DISKCOMP COM 1640 5-07-82 12:00 pm 47 52 COMP COM 1649 5-07-82 12:00 pm 51 56 EXE2BIN EXE 1280 5-07-82 12:00 pm 55 60 MODE COM 2509 5-07-82 12:00 pm 58 63 EDLIN COM 2392 5-07-82 12:00 pm 63 68 DEBUG COM 5999 5-07-82 12:00 pm 68 73 LINK EXE 41856 5-07-82 12:00 pm 80 85 BASIC COM 11392 5-07-82 12:00 pm 162 167 BASICA COM 16768 5-07-82 12:00 pm 185 190 Absolute Sector 4 ----------------- ART BAS 1920 5-07-82 12:00 pm 218 223 SAMPLES BAS 2432 5-07-82 12:00 pm 222 227 MORTGAGE BAS 6272 5-07-82 12:00 pm 227 232 COLORBAR BAS 1536 5-07-82 12:00 pm 240 245 CALENDAR BAS 3840 5-07-82 12:00 pm 243 248 MUSIC BAS 8704 5-07-82 12:00 pm 251 256 DONKEY BAS 3584 5-07-82 12:00 pm 268 273 CIRCLE BAS 1664 5-07-82 12:00 pm 275 280 PIECHART BAS 2304 5-07-82 12:00 pm 279 284 SPACE BAS 1920 5-07-82 12:00 pm 284 289 BALL BAS 2048 5-07-82 12:00 pm 288 293 COMM BAS 4352 5-07-82 12:00 pm 292 297 Last used cluster/sector on diskette: 300 305 Unused sectors at end of diskette = 14 |
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:
05b9205ee6fa56cecbc5bf22b5b34555 IBMBIO.COM 4cf27775844f90c7d4b615131dc9d0e5 IBMDOS.COM f95a073439e1ee7c9b0c9d37d42de7fe COMMAND.COM 31b9c8001d7e9d9e98808b93badf4b98 FORMAT.COM 23424d1ee8fd418f5c770457439dcab2 CHKDSK.COM f4759b60f3a5fb8b8323ced9b2437e5a SYS.COM aa465c0204b780ad73572c2220f7c231 DISKCOPY.COM b58414f95b22b95d0fa36a7314a75536 DISKCOMP.COM d2e84db1228b4371202bd3a81e19c51a COMP.COM 97d848f6216dfb22428793e8f09877ff EXE2BIN.EXE 08f99d509a3b6855ea992f3f7af0e6e7 MODE.COM 78f7965a01690258f57abb89fa9e6f3c EDLIN.COM e35e225c5fd5ada608c72fe17ccad0cf DEBUG.COM b9103931cd3d05aad7f76bab57cae6f0 LINK.EXE 5bb691f37298f553e0ca933d23cbb5a5 BASIC.COM a06e6df77c54d2b13506a2ba41e70518 BASICA.COM a1ab28c1e54ec1647eebe021c7a2b2ba ART.BAS 10dbd8e1c0276930e1a113e513da235d SAMPLES.BAS c5f9ba1c20ff07291d0dc37f80a4bb56 MORTGAGE.BAS 5d2b5c4979806d5d2d83bc04a4fbcedb COLORBAR.BAS ada93f706eee602187298c37636e278f CALENDAR.BAS 488cd80e721ab7c18b60132f505aa0cb MUSIC.BAS e09be04b3a7635cdb8671b36596b58e5 DONKEY.BAS a9ca3dddb9302af9d67ed20da440ba0d CIRCLE.BAS f97480c4398dd5eca5f6ab029ac0c134 PIECHART.BAS 8b44decbc81ae291a964a2063820e286 SPACE.BAS d6e5631740f25e6f4bebe2742f385775 BALL.BAS ee431c39b050784d192d0b530b431404 COMM.BAS
On our Forensic Examination page, we've also included the MD5 checksum for an image file of the whole diskette! (Note: There's at least one other image file floating around 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 hash value! So even though every file above will match those from the other image file, it's checksum is is completely different than our MD5 hash.)
NOTE: This is still a work in progress!
Last Update: 13 August 2008 (13-08-2008).
You can write to me using this: online reply form. (It opens in a new window.)
IBM
PC DOS 1.00 Index
MBR
and Boot Records Index
The Starman's Realm Index