OS/2 1.x Pre-Release

OS/2 was originally a joint effort between IBM and Microsoft. It grew out of efforts to create a Multitasking MS-DOS. It was intended to be the future OS for IBM's new PS/2 series. At release it competed against Microsoft's Windows GUI shell, but most users continued to use DOS. OS/2 1.x was used as the basis for Citrix Multiuser

1.x was heavily criticized for its poor backwards compatibility, heavier system requirements, design decisions made in order to support 286s instead of just 386s, poor hardware compatibility, and lack of third party driver support. There was an inaccurate, but justifiable, common belief that OS/2 could only run on genuine IBM hardware.

Still, it was believed that all future software development would be for OS/2, until an almost overnight fallout between IBM and Microsoft shifted the spotlight to the yet to be developed Windows NT.

Without Microsoft's help, IBM massively re-wrote OS/2 to produce OS/2 2.x

Other OS/2 Versions:
| 1.x | 2.x | 3.x | 4.x | All |

Release notes

Below are several OS/2 pre-release prototypes.

SIZZLE: the code-name for a pre-1.0 version of OS/2 with a collection of changes intended to improve overall OS/2 performance.

Football: based on pre-1.0 OS/2 sources, demonstrated multiple DOS applications running in V86-mode. Became part of OS/2 2.0.

OS/2 1.0 Debugger Disk: version of OS/2 1.0 which included the built-in kernel debugger used by Microsoft and IBM for internal development, along with a rudimentary program selector.

Product type
Release date
User interface
Download count
41 (0 for release)


Download name Version Language Architecture File size Downloads
OS2 1.0 Debugger Disk (October 12 1988) (5.25-1.2mb) 1.0 Debugger Disk (October 12 1988) English 355.82KB 0
OS2 CP-DOS Boot Disk (v7.68) (October 22 1986) (5.25-1.2mb) CP-DOS Boot Disk (v7.68) English 336.93KB 0
OS2 FOOTBALL Boot Disk (v4.41.00) (December 1987) (5.25-1.2mb) FOOTBALL Boot Disk (v4.41.00) English 355.6KB 0
OS2 FOOTBALL Boot Disk (v7.68.17) (February 1987) (5.25-1.2mb) FOOTBALL Boot Disk (v7.68.17) English 382.34KB 0
OS2 SIZZLE Boot Disk (v7.68.18 DEBUG) (January 7 1987) (5.25-1.2mb) SIZZLE Boot Disk (v7.68.18 DEBUG) English 457.08KB 0
OS2 SIZZLE Boot Disk (v7.68.18) (October 22 1986) (5.25-1.2mb) SIZZLE Boot Disk (v7.68.18) English 447.64KB 0


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