Trying out Microsoft's pre-release OS/2 2.0

It fell through a timewarp from an alternate and very different computing universe

The earliest known release of Microsoft's 32-bit version of OS/2 is now out there, and intrepid code archeologists have it running. It's a glimpse into an alternatve computing universe.

The long-lost Microsoft OS/2 2 – BNIB, as they say on certain popular online auction sites.

The long-lost Microsoft OS/2 2 – BNIB, as they say on certain popular online auction sites (click to enlarge)

Last month we covered the news of the discovery and purchase of the only known surviving copy of 32-bit OS/2 from Microsoft – as opposed to the IBM version, the one which became a retail product and a descendant of which is still around today.

Reg reader Brian Ledbetter bought it, opened the still-sealed box, imaged the disks, and even managed to install it and take a few screenshots. Now, two of the internet's experts in getting early PC operating systems running today have managed to fire it up, and you can see the results.

Why such interest in this nearly third-of-a-century old, unreleased OS? Because this is the way the PC industry very nearly went. This SDK came out in June 1990, just one month after Windows 3.0. If 32-bit OS/2 had launched as planned, Windows 3 would have been the last version before it was absorbed into OS/2 and disappeared. There would never have been any 32-bit versions: no Windows NT, no Windows 95; no Explorer, no Start menu or taskbars. That, in turn, might well have killed off Apple as well. No iPod, no iPhone, no fondleslabs. Twenty-first century computers would be unimaginably different.

The surprise here is that we can see a glimpse of this world that never happened. The discovery of this pre-release OS shows how very nearly ready it was in 1990. IBM didn't release its solo version until April 1992, the same month as Windows 3.1 – but now, we can see it was nearly ready two years earlier.

This is a version message nobody has seen in over a third of a century.

This is a version message nobody has seen in over a third of a century

That's why Michal Nečásek of the OS/2 Museum called his look The Future That Never Was. He uncovered a couple of significant bugs, but more impressively, he found workarounds for both, and got both features working fine.

OS/2 2 could run multiple DOS VMs at once, but in the preview, they wouldn't open – due to use of an undocumented instruction which Intel did implement in the Pentium MMX and later processors. Secondly, the bundled network client wouldn't install – but removing a single file got that working fine. That alone is a significant difference between Microsoft's OS/2 2.0 and IBM's version: Big Blue didn't include networking until Warp Connect 3 in 1995.

His verdict?

The 6.78 build of OS/2 2.0 feels surprisingly stable and complete. The cover letter that came with the SDK stressed that Microsoft developers had been using the OS/2 pre-release for day-to-day work.

Over at Virtually Fun, Neozeed also took an actual look at Microsoft OS/2 2.0, carefully recreating that screenshot from PC Magazine in May 1990. He even managed to get some Windows 2 programs running, although this preview release did not yet have a Windows subsystem.

The preview release has the Desktop Manager and File Manager UI of OS/2 1.x – and Windows 3.x

The preview release has the Desktop Manager and File Manager UI of OS/2 1.x – and Windows 3.x (click to enlarge)

On his Internet Archive page, he has disk images and downloadable virtual machines so that you can run this yourself under VMware or 86Box.

The other leg of the Trousers of Time

If we try to put this in historical context, it may help to explain why people are so interested in this. IBM invented the PC, but it didn't develop the machine's OS. Neither did Microsoft: it licensed it in from Seattle Computer Products, as we described in January when the oldest known version was rediscovered.

In 1987, IBM announced the second generation of the PC platform and its operating system. The hardware part was the PS/2 range of computers, whose legacy includes PS/2 mouse and keyboard ports, the VGA graphics standard and monitor plug, and 3.5 inch 1.4MB floppies. The software part was OS/2: the planned future of PC operating systems, co-developed with Microsoft.

OS/2 was designed and planned to overcome all the biggest limitations of MS-DOS: just one program running at a time, limited to 1MB of RAM (less quite a lot of space for ROMs, I/O ports and things), a maximum of 32MB per disk partition, 8.3-character filenames, and no built-in networking or standard GUI.

The problem was, however, that OS/2 version 1.x targeted 80286 computers. The 16-bit 80286 processor, released in 1982, had many limitations compared to the 80386, which was released in 1985 – two years before OS/2 1.0. It wasn't that the 80386DX could address an inconceivable 4GB of RAM, 256 times more than the 80286. The key feature was that the '386 could multitask multiple DOS virtual machines. In 1987, Microsoft had already demonstrated an OS/2 prototype codenamed FOOTBALL which could multitask several DOS apps. You can even try it in your browser.

When OS/2 launched, almost anyone who could afford computers for work ran DOS. All the key business programs in the world were DOS apps. OS/2 1.x's fancy multitasking was worthless, because it didn't work with the software already out there. It's generally believed that targeting OS/2 1 at the '286 was at the insistence of IBM, which had sold a lot of expensive 80286-based PS/2s. It had promised those customers OS/2.

At the time, the Reg FOSS desk was a callow young software-support bod for an IBM reseller, worked on a lot of Model 50 and Model 60 PS/2s, and can attest that most of those customers neither knew nor cared. Anyone choosing IBM kit was not a price-sensitive buyer.

OS/2 1 flopped.

For a third of a century, the way the history has been told is that an internal skunkworks project at Microsoft became Windows 3.0, it was a surprise hit, and as a result, Microsoft dropped out of the OS/2 project to pursue Windows instead. IBM continued on its own, first, and arguably fatally, putting out OS/2 1.3, then finishing OS/2 2.0 and releasing it much later, in 1992 – when it was too little, too late.

This unfinished preview release of OS/2 2.0 shows that the story wasn't so simple. IBM didn't heroically struggle on alone for two more years to complete OS/2 2. Getting build 6.78 running shows that the year Microsoft released Windows 3.0, it already had a working 32-bit OS/2 2.0, almost ready to go.

Youtube Video


In our previous story, we didn't spell this part out clearly enough and some readers missed it: what turned up on eBay was Microsoft's pre-release 32-bit OS/2 software development kit – but along with the SDK's compilers and so on came a preview release of the OS itself. Other versions of the SDK are out there, but they don't contain the actual OS, which for 34 years was only known from a few ancient screenshots.

What Mr Ledbetter bought is Preview Release 2. As that number implies, there was a Preview Release 1 of Microsoft's OS/2 2 SDK, and the OS/2 Museum has a copy of the new release from December 29, 1989. Sadly, though, that may be lost forever. ®

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