Trying Out Microsoft’s Pre-Release OS/2 2.0

Last month, the only known surviving copy of 32-bit OS/2 from Microsoft was purchased for $650. “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,” reports The Register. From the report: 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.

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