Two Stop Bits | >There is a difference between the Microsoft and IBM versions of OS/2 that c...

glhaynes 404 days ago | parent

>There is a difference between the Microsoft and IBM versions of OS/2 that clearly stems from Bill Gates’ feelings about the 286. In the Microsoft release should the kernel detect an Intel 80386, MS-DOS real mode applications would run via instructions to switch modes between real and protected. In the IBM version this didn’t happen. IBM only implemented the method employed for the 80286 which was to triple fault the CPU, trigger a shutdown cycle, have the motherboard reset the CPU, and have BIOS skip post and jump to a specified memory address immediately following the return of CPU execution. For retro enthusiasts, try to find Microsoft’s OS/2 for your 386.

I was an OS/2 user back in the day and have never heard about this difference! I was under the impression that IBM OS/2 and MS OS/2 were functionally identical. I wonder what difference this made for users.

CWuestefeld 404 days ago
That is interesting. Although I only ever used the MS version on 286. This was the very first version of OS/2, the "text mode only" version mentioned in the article, when Presentation Manager (the windowing GUI) was a separate program.
At the time, I worked on an office suite called Enable, which featured strong spreadsheet, word processing, and dbase-like database applications. Windows existed, but wasn't successful yet, and for some time we were explicitly testing for compatibility with OS/2.
Later on, at the time OS/2 2 and Warp came out, I was working at IBM. The frustration there, among the people who cared at all, was palpable. They really believed they had a superior product, and largely blamed IBM management and marketing organizations for its failure.