39 lines
2.1 KiB
Markdown
39 lines
2.1 KiB
Markdown
---
|
|
layout: post
|
|
title: Early OS/2 Artifacts
|
|
date: 2016-01-23 14:00:00
|
|
category: OS/2
|
|
permalink: /blog/2016/01/23/
|
|
---
|
|
|
|
Before OS/2 was named **OS/2** by IBM on April 2, 1987, the operating system was known by many different names at
|
|
Microsoft as it evolved, including **DOS5**, **MT-DOS**, **CP-DOS**, and **ADOS**.
|
|
|
|
In late 1986, Microsoft began working on a couple different branches. One was called **SIZZLE**, where a variety of
|
|
performance improvements were tested before being merged back into the main branch.
|
|
|
|
Another branch was **FOOTBALL** (aka **PIGSKIN**), an early 80386-based prototype intended to test the viability
|
|
of the running multiple DOS applications in V86-mode. Sometimes this 80386 version was also called **386DOS**,
|
|
to distinguish it from **286DOS**. More details are in this
|
|
[FOOTBALL Design Document](/disks/pcx86/os2/misc/football/87058/#football-design-document).
|
|
|
|
To shed some light on those efforts, I recently added a few [OS/2 Prototype Disks](/disks/pcx86/os2/misc/): a small
|
|
collection of early (mostly pre-1.0) OS/2 boot disks that provide a glimpse of what some of those early OS/2 builds
|
|
looked like.
|
|
|
|
Getting these early versions of OS/2 to run in **PCjs** has been a bit of a challenge. There have been some successes
|
|
but also some lingering issues. Debugging continues.
|
|
|
|
Part of the problem is that these pre-1.0 builds still contain a few bugs. Also, the original
|
|
[OS/2 FOOTBALL Boot Disk](/disks/pcx86/os2/misc/football/87058/) from February 1987 was developed and
|
|
tested exclusively on Compaq DeskPro 386 machines from late 1986, so it has some uncommon 80386 dependencies:
|
|
|
|
* The [80386 LOADALL](/pubs/pc/reference/intel/80386/loadall/) instruction
|
|
* 32-bit segment register writes must modify only 16 bits of memory
|
|
|
|
**FOOTBALL** also had some specific video hardware requirements: CGA or EGA. Note that the VGA, which is what most
|
|
emulators use by default these days, did not exist in 1986. The VGA was introduced in April 1987, when IBM
|
|
unveiled their new PS/2 hardware line -- and announced OS/2.
|
|
|
|
*[@jeffpar](http://twitter.com/jeffpar)*
|
|
*January 23, 2016*
|