MS-DOS 2

(Redirected from MS-DOS 2.01a)
MS-DOS 2
Version of MS-DOS
MS-DOS 2.00 Eagle OEM 1.01.png
Version2.x
Release date1983-03
Replaces
MS-DOS 1
Replaced by
MS-DOS 3

MS-DOS 2 is a family of versions of MS-DOS, initially released in March 1983.

MS-DOS 2.00[edit | edit source]

MS-DOS 2.00 was released in March 1983 and introduced support for subdirectories and hard drives (with capacity up 10 MB). New commands (both internal and external) were included as well, such as PRINT.

Gallery[edit | edit source]

MS-DOS 2.01[edit | edit source]

MS-DOS 2.01 was released in November 1983. It added international support via the COUNTRY command from CONFIG.SYS, where the user can change the time, date and currency formats to suit the country where the user originates. This version also added support for over 7000 Japanese kanji characters.

Gallery[edit | edit source]

MS-DOS 2.01a[edit | edit source]

MS-DOS 2.01a is the Wang Professional Computer OEM of MS-DOS 2.01, released in 1985.

Gallery[edit | edit source]

MS-DOS 2.05[edit | edit source]

MS-DOS 2.05 was released in October 1983 as an OEM version for the DEC Rainbow 100 computer only.[1]

Gallery[edit | edit source]

MS-DOS 2.10[edit | edit source]

MS-DOS 2.10 was released in 1985 as an OEM version for the Eagle 1600, Eagle PC, Eagle PC Plus, Eagle Spirit and Eagle Turbo computers only.

MS-DOS 2.11[edit | edit source]

MS-DOS 2.11 was released in October 1983 by a number of OEMs. In 2014, Microsoft for the first time published the source code for this version and MS-DOS 1.25.

Source code[edit | edit source]

Microsoft published the source code of:

  • CHKDSK.COM
  • COMMAND.COM
  • DEBUG.COM
  • DISKCOPY.COM
  • EDLIN.COM
  • EXE2BIN.EXE
  • FC.EXE
  • FIND.EXE
  • FORMAT.COM (partial)
  • IO.SYS (partial)
  • MORE.COM
  • MSDOS.SYS
  • PRINT.COM
  • RECOVER.COM
  • SORT.EXE
  • SYS.COM

The OEMs were expected to supply their own FDISK.COM (if they wish to support hard drive), IO.SYS (for their own machine containing their own copyright strings), a more usable FORMAT.COM with a boot sector and any apps they wish to include (BACKUP, RESTORE and etc.). Some OEMs customized this version of MS-DOS to support 720KB 3.5" floppy drives.

Same as earlier versions of MS-DOS, the original non-OEM .COM binary files contain the string Ver x.xx (from HEADER DB "Vers x.xx" in the source code).

Interestingly, this version of MS-DOS's MSDOS.SYS and COMMAND.COM reports the same version upon boot.

Gallery[edit | edit source]

MS-DOS 2.12[edit | edit source]

MS-DOS 2.12 was released in December 1984 as an OEM version for Compaq personal computers.[2]

Gallery[edit | edit source]

MS-DOS 2.21[edit | edit source]

MS-DOS 2.21 is mentioned in the source code for Windows NT 3.5 build 782 in the file DBCS.C.

      /*
      ** Get DBCS lead byte table.  This function has been supported since
      ** DBCS MS-DOS 2.21.
      */

MS-DOS 2.25[edit | edit source]

MS-DOS 2.25 is the last version from the MS-DOS 2 family, released in October 1985.[3] It included support for extended non-ASCII character sets.[4][5]

References[edit | edit source]

  1. "MS DOS® Version 2.05 - Digital OEM". The Internet's Premiere DOS Version Resource. Archived from the original on 1 October 2020.
  2. "MS DOS® Version 2.12 - Compaq OEM". The Internet's Premiere DOS Version Resource. Archived from the original on 7 October 2020.
  3. Competition in the Computer Industry: Hearing Before the Subcommittee on Economic and Commercial Law of the Committee on the Judiciary, House of Representatives, One Hundred Third Congress, First Session, October 13, 1993. U.S. Government Printing Office, 1994. p. 20.
  4. Zheng, Qin; Huidi, Zhang; Xin, Qin; Kaiping, Xu; Kouemo Ngayo Anatoli, Dimitrov; Guolong, Wang; Wenhui, Yu. (17 July 2018) Fundamentals of Software Culture. Springer. p. 91. ISBN 978-9811307010.
  5. Simrin, Steven (1988). The Waite Group's MS-DOS Bible. H.W. Sams. p. 466. ISBN 978-0672226175.