MS DOS® Version 1.25 - Zenith OEM





Labels used with permission of Zenith® Corporation
Labels copyright © Zenith® Corporation

Boot Screen:


Z-DOS/MS-DOS release 1.01, version 1.25

(C) 1982 Zenith Data Systems



Z-DOS/MS-DOS Command release 1.00, version 1.20

Current date is Tue 9-15-82

Enter new date:

Current time is 8:23:15.37

Enter new time:



A>_


Package Contents:

Package images used with permission
Zenith® Corporation
Binder, Volume 1, P/N: 593-0042-01
Flysheet P/N: 597-2810-01
Manual P/N: 595-2827-01
Winchester Supplement, P/N: 595-2854
Binder, Volume 2, P/N: 593-0051-01
Flysheet P/N: 597-2869-01
Manual P/N: 595-2835-01
Quick Reference, P/N: 595-2984
Disk 1, P/N: 448-447 E
Disk 2, P/N: 448-447 A
Letter, Winchester Supplement #1, P/N: 597-3171
Letter, Winchester Supplement #2, P/N: 591-4105
Letter, BIOS modification, P/N: 591-3955
Plastic binder tab set, P/N: 597-2830
(already installed in our specimen)
Tab set instruction card, P/N: None

Collector's notes:

One of several Zenith Data Systems OEM ports from Microsoft, this version was the first release of Z-DOS. Very large binders (12" x 10.5"). Several hundred pages in manuals.
Rated: Very Rare.
Estimated Value: Mint-$500 VG-$350 G-$300

Vital Statistics:

Release Date: May, 1983
Disks in Set: 2
Diskette Form Factor:5.25", DSDD, 9 sectors per track
Capacity: 360k
Sector Size: 512 bytes
Track Size: 9 sectors
48 tracks per inch - disk 1
40 tracks per inch - disk 2
Disk Sides: 2
Version String:

Note - we do not provide the sector and offset address for this version string. This is due to the fact we had to copy the BIOS and kernel files off the original disk format of 48 TPI to a 40 TPI floppy, resulting is a relocation of the files relative to their offset location. These are still the genuine strings.



0D 0A 5A 2D 44 4F 53 2F 4D 53 2D 44 4F 53 20 72 ¦   Z-DOS/MS-DOS r

65 6C 65 61 73 65 20 31 2E 30 31 2C 20 76 65 72 ¦ elease 1.01, ver

73 69 6F 6E 20 31 2E 32 35 0D 0A 28 43 29 43 6F ¦ sion 1.25  (C)Co

70 79 72 69 67 68 74 20 31 39 38 32 20 5A 65 6E ¦ pyright 1982 Zen

69 74 68 20 44 61 74 61 20 53 79 73 74 65 6D 73 ¦ ith Data Systems

F3 04 E9 10 FC 0D 0A 5A 2D 44 4F 53 2F 4D 53 2D ¦        Z-DOS/MS-

44 4F 53 20 43 6F 6D 6D 61 6E 64 20 72 65 6C 65 ¦ DOS Command rele

61 73 65 20 31 2E 30 30 2C 20 76 65 72 73 69 6F ¦ ase 1.00, versio

6E 20 31 2E 32 30 0D 0A 24 00 00 00 00 00 00 00 ¦ n 1.20  $


Disk 1: IO SYS 11,009 04-15-83 9:08a SH Z-DOS SYS 6,222 01-31-83 9:21a SH ALTCHAR SYS 431 06-24-82 6:10p COMMAND COM 5,114 01-25-83 2:36p DEBUG COM 6,003 01-31-83 9:18a EDLIN COM 2,313 01-31-83 9:19a CHKDSK COM 1,754 01-31-83 9:19a SYS COM 637 01-31-83 9:19a FORMAT COM 10,542 05-27-83 9:53a A CONFIGUR COM 7,921 02-18-83 8:22a MAP COM 2,291 05-27-83 8:53a DSKCOPY COM 12,350 05-23-83 12:55p A DSKCOMP COM 1,528 01-31-83 9:19a MAKE COM 13,310 05-27-83 9:54a A PRINT COM 1,740 01-31-83 9:20a PSC ASM 5,760 01-31-83 9:18a FILCOM COM 8,320 01-31-83 9:19a MASM EXE 70,784 01-31-83 9:20a LINK EXE 41,856 01-31-83 9:20a LIB EXE 32,128 01-31-83 9:20a CREF EXE 13,824 01-31-83 9:20a EXE2BIN EXE 1,280 01-31-83 9:20a BACKUP EXE 49,920 05-27-83 9:56a A AUTOEXEC BAT 53 01-31-83 9:19a SYSCOPY DAT 813 06-23-82 8:34a 25 file(s) 307,903 bytes 2,048 bytes free 322,560 bytes total disk space 18,432 bytes in 2 hidden files 302,080 bytes in 23 user files 2,048 bytes available on disk 1,024 bytes in each allocation unit 315 total allocation units on disk 2 available allocation units on disk Disk 2: RESTORE EXE 23,936 02-25-83 12:01p MEMTST EXE 4,992 01-31-83 9:20a RDCPM COM 3,754 03-03-83 1:26p GRAPHICS CHR 431 06-24-82 6:10p ENGLISH CHR 441 06-24-82 6:08p FRENCH CHR 633 06-24-82 6:08p GERMAN CHR 617 06-24-82 6:08p DANISH CHR 523 06-24-82 6:09p SWEDISH CHR 523 06-24-82 6:09p SPANISH CHR 531 06-24-82 6:08p ITALIAN CHR 651 06-24-82 6:11p DATCOPY DAT 848 06-23-82 8:53a BMSDOS ASM 14,464 03-17-83 9:21a BCHR ASM 1,536 04-15-83 8:30a BDSK ASM 1,408 01-31-83 9:22a BEND ASM 256 01-31-83 9:19a DEFASCII ASM 640 01-31-83 9:19a DEFCONFG ASM 5,376 02-22-83 3:03p DEFMTR ASM 2,944 01-31-83 9:19a DEFFMT ASM 1,408 01-31-83 9:19a DEF6821 ASM 1,536 01-31-83 9:19a DEFEP2 ASM 2,560 01-31-83 9:21a DEFCHR ASM 6,144 01-31-83 9:21a DEF8253 ASM 883 01-31-83 9:19a DEF8259A ASM 2,017 01-31-83 9:19a DEF6845 ASM 1,664 01-31-83 9:21a DEFZ207 ASM 3,584 01-31-83 9:18a DEFZ217 ASM 4,608 01-31-83 9:23a DEFDSK ASM 4,480 01-31-83 9:19a DEFMS ASM 9,600 04-15-83 8:24a DEFIPAGE ASM 3,328 01-31-83 9:22a PARMS ASM 512 01-31-83 9:21a DEFSBC ASM 1,792 01-31-83 9:22a BINIT ASM 45,952 04-05-83 8:44a BDOSTB ASM 4,224 01-31-83 9:27a BCHRIO ASM 54,400 04-15-83 8:26a BCONIO ASM 2,560 01-31-83 9:19a BPRNIO ASM 640 01-31-83 9:18a BAUXIO ASM 1,280 01-31-83 9:22a BDSKIO ASM 4,608 01-31-83 9:18a BDSKLA ASM 7,040 01-31-83 9:19a BCLOCK ASM 8,064 02-22-83 3:07p DSK ASM 49,920 01-31-83 3:50p BDSKTB ASM 11,264 01-31-83 9:23a DOBIOS BAT 512 01-31-83 9:19a MACLIB ASM 896 01-31-83 9:19a BMSDOSL 48 01-31-83 9:18a 47 file(s) 300,028 bytes 1,024 bytes free 322,560 bytes total disk space 321,536 bytes in 47 user files 1,024 bytes available on disk 1,024 bytes in each allocation unit 315 total allocation units on disk 1 available allocation units on disk

MD5 Signatures:

IO.SYS C9242087E6AF75F93BA98ACF6FBA9739 Z-DOS.SYS 96DB4573E84FD70B5B198E7821BA4CF3 COMMAND.COM 94E6E56F240D3964550537E2C60A6841 VER command: Not available

Version History:

MS-DOS 1.25, aka Zenith DOS 1.25, was one of Microsoft's first OEM releases (not counting IBM). It was custom-made for the Zenith Z-100 desktop PC, a hybrid system that ran dual processors - an Intel 8085 to run CP/M programs, and an Intel 8088 to run DOS. The system was also dual-branded by Zenith and Heath, as the Z-100 and the H-100 respectively. The system design was industrial and many saw military service. Of note is the Zenith system was MS-DOS compatible after a custom rewrite of the MSDOS.SYS file as Z-DOS.SYS, but it was not IBM-PC compatible in the sense of architecture (IBM using an 8-bit ISA design and Zenith using a 8-bit S-100 design). This version of DOS introduced support for double-sided diskettes. ZDOS version 1.25 came in two releases - sub-version 1.01, which only supported floppy disk drives, and sub-version 1.10, which added support for Winchester hard disk drives.