7 ms·

It is, especially in hindsight, difficult to appreciate how big a deal DPMI was. But to try to give you an idea: I was in an OS/2 seminar (because, well, OS/2

It is, especially in hindsight, difficult to appreciate how big a deal DPMI was. But to try to give you an idea: I was in an OS/2 seminar (because, well, OS/2 was the future at that point in time) when someone from Microsoft circulated photocopies of an early DPMI document. This instantly divided the audience in two groups: those who got it (and abandoned the OS/2 hype train that instant), and those who did not. When (some years later: Internet time was not yet invented either) Windows 95 came out with pretty much flawless DOS compatibility, whereas OS/2 was still struggling to run more than one DOS app simultaneously (with DOS apps still being very much the only revenue-positive game in town), OS/2 was effectively dead. Sure, NT put the nails in the coffin, but it would be a few years before typical consumer/business hardware could reliably run that. With DPMI (an API, not even a product...), Microsoft settled the OS wars (as they were at the time...) decisively.

dale_glass 3y ago
> This instantly divided the audience in two groups: those who got it (and abandoned the OS/2 hype train that instant), and those who did not. Why? Was there something stopping OS/2 from implementing DPMI as well?
- fredoralive 3y ago
  Why develop for OS/2 when you can use protected mode from DOS anyway? OS/2 2.0 added DPMI support so it can run there, although this anecdote is presumably from the OS/2 1.x era.
  - dale_glass 3y ago
    > Why develop for OS/2 when you can use protected mode from DOS anyway? GUI? Multitasking? But was it even viable to use anything but DOS for gaming back then? WinG/DirectX took a good while to show up, and I'm not sure if OS/2 ever developed anything comparable. Windows gaming was mostly things like chess and solitaire until then.
  - sillywalk 3y ago
    Why develop for OS/2? Unless you actually bought an IBM machine, it probably didn't have OS/2 installed. So you would need to actually buy OS/2, (and also a RAM upgrade, with OS/2 needing more than Windows 3.x), and if you wanted to run (16bit) Windows Apps, I believe you needed to buy the more expensive "Blue Spine" version.
    - bzzzt 3y ago
      I knew of a few people who got OS/2 as a pack-in with a new PC clone from a big store chain in that time (it was Escom I believe). Apparently, IBM also tried bundling as a way to increase market share.
- JdeBP 3y ago
  There wasn't, and it in fact did.
pavlov 3y ago
> “Windows 95 came out with pretty much flawless DOS compatibility, whereas OS/2 was still struggling to run more than one DOS app simultaneously” This doesn’t match my recollection. Yes, 16-bit OS/2 1.x did poorly with DOS because it couldn’t use the 386 virtualization capabilities, but 32-bit OS/2 2.x was a great environment for multitasking DOS apps. It definitely supported DPMI too. Many people ran complex apps like 3D Studio under OS/2 rather than plain DOS. It even had the ability to preemptively multitask Windows 3.0 apps which Windows itself didn’t. IBM used to have a marketing slogan for OS/2: “A better DOS than DOS and a better Windows than Windows.” Unfortunately that was a fairly niche market after all. People didn’t want a somewhat better environment for running Windows apps in parallel sandboxes when it came with so much installation hassle and such high system requirements. With practically no native apps and losing the ability to run Windows soon (since IBM’s license only covered Windows 3.x), it had no chance.
- Lerc 3y ago
  When it came to games I had written I had relied on promises that Microsoft had made that dos virtualization would be quite seamless. My game used a pseudo retrace interrupt by carefully calibrating the timer every frame to generate an interrupt just before the screen retrace and adjusting the timer to compensate for drift. This did not work in Windows95. OS/2 did it almost perfectly (it missed the occasional frame but not enough to matter)
- pdonis 3y ago
  > t even had the ability to preemptively multitask Windows 3.0 apps which Windows itself didn’t. I remember this as well. For a while I was running Windows apps on OS/2 Warp instead of Windows for just this reason.
- bane 3y ago
  I remember also that it was quite flaky. My recollection, probably wrong, was that DOS software that really pushed the system in certain ways wouldn't work right under Win95, especially audio stuff. I used to work with Impulse Tracker and spend lots of time with the Demoscene and IIR there was a way to kill Win95 and drop back to pure DOS (or boot into DOS instead) and things worked fine there. Windows 95 in that sense still just felt like a very powerful shell over MS-DOS like Windows 3.1 and it wasn't until we got the NT derivatives (XP etc.) that I, and the demoscene, reluctantly gave up on DOS mode software. It took the scene a very long time to bounce back from that transition, and in some ways it came out of it a very different scene.
dylan604 3y ago
>When (some years later: Internet time was not yet invented either) Windows 95 came out I'm sorry, but I was on the internet before 1995
- ido 3y ago
  Internet Time, not internet.
JdeBP 3y ago
This story is mixing up the situations of 1987 with OS/2 1.x and of 1995 with DOS+Windows 95. By the time of the latter, OS/2 1.x was long past. 32-bit OS/2 used v8086 to run multiple Virtual DOS Machines and had DPMI support in them provided by the VDPMI.SYS virtual device driver.
michaelcampbell 3y ago
> whereas OS/2 was still struggling to run more than one DOS app simultaneously That was hardly universal. I remember running multiple dos-native _games_ on os/2. Yeah, they were slow; they were slow when running under DOS as the only app running, but they ran. I never had any compatibility issues. It was one of the most "fun" OS's I've ever hit.
AtlasBarfed 3y ago
OS/2 needed to be free with enterprise support a paid feature. If IBM did that it would have had a shot. Of course, no way IBM would have done that.

dale_glass 3y ago

> This instantly divided the audience in two groups: those who got it (and abandoned the OS/2 hype train that instant), and those who did not. Why? Was there something stopping OS/2 from implementing DPMI as well?

fredoralive 3y ago
Why develop for OS/2 when you can use protected mode from DOS anyway? OS/2 2.0 added DPMI support so it can run there, although this anecdote is presumably from the OS/2 1.x era.
- dale_glass 3y ago
  > Why develop for OS/2 when you can use protected mode from DOS anyway? GUI? Multitasking? But was it even viable to use anything but DOS for gaming back then? WinG/DirectX took a good while to show up, and I'm not sure if OS/2 ever developed anything comparable. Windows gaming was mostly things like chess and solitaire until then.
- sillywalk 3y ago
  Why develop for OS/2? Unless you actually bought an IBM machine, it probably didn't have OS/2 installed. So you would need to actually buy OS/2, (and also a RAM upgrade, with OS/2 needing more than Windows 3.x), and if you wanted to run (16bit) Windows Apps, I believe you needed to buy the more expensive "Blue Spine" version.
  - bzzzt 3y ago
    I knew of a few people who got OS/2 as a pack-in with a new PC clone from a big store chain in that time (it was Escom I believe). Apparently, IBM also tried bundling as a way to increase market share.
JdeBP 3y ago
There wasn't, and it in fact did.

pavlov 3y ago

> “Windows 95 came out with pretty much flawless DOS compatibility, whereas OS/2 was still struggling to run more than one DOS app simultaneously” This doesn’t match my recollection. Yes, 16-bit OS/2 1.x did poorly with DOS because it couldn’t use the 386 virtualization capabilities, but 32-bit OS/2 2.x was a great environment for multitasking DOS apps. It definitely supported DPMI too. Many people ran complex apps like 3D Studio under OS/2 rather than plain DOS. It even had the ability to preemptively multitask Windows 3.0 apps which Windows itself didn’t. IBM used to have a marketing slogan for OS/2: “A better DOS than DOS and a better Windows than Windows.” Unfortunately that was a fairly niche market after all. People didn’t want a somewhat better environment for running Windows apps in parallel sandboxes when it came with so much installation hassle and such high system requirements. With practically no native apps and losing the ability to run Windows soon (since IBM’s license only covered Windows 3.x), it had no chance.

Lerc 3y ago
When it came to games I had written I had relied on promises that Microsoft had made that dos virtualization would be quite seamless. My game used a pseudo retrace interrupt by carefully calibrating the timer every frame to generate an interrupt just before the screen retrace and adjusting the timer to compensate for drift. This did not work in Windows95. OS/2 did it almost perfectly (it missed the occasional frame but not enough to matter)
pdonis 3y ago
> t even had the ability to preemptively multitask Windows 3.0 apps which Windows itself didn’t. I remember this as well. For a while I was running Windows apps on OS/2 Warp instead of Windows for just this reason.
bane 3y ago
I remember also that it was quite flaky. My recollection, probably wrong, was that DOS software that really pushed the system in certain ways wouldn't work right under Win95, especially audio stuff. I used to work with Impulse Tracker and spend lots of time with the Demoscene and IIR there was a way to kill Win95 and drop back to pure DOS (or boot into DOS instead) and things worked fine there. Windows 95 in that sense still just felt like a very powerful shell over MS-DOS like Windows 3.1 and it wasn't until we got the NT derivatives (XP etc.) that I, and the demoscene, reluctantly gave up on DOS mode software. It took the scene a very long time to bounce back from that transition, and in some ways it came out of it a very different scene.

dylan604 3y ago

>When (some years later: Internet time was not yet invented either) Windows 95 came out I'm sorry, but I was on the internet before 1995

ido 3y ago
Internet Time, not internet.

JdeBP 3y ago

This story is mixing up the situations of 1987 with OS/2 1.x and of 1995 with DOS+Windows 95. By the time of the latter, OS/2 1.x was long past. 32-bit OS/2 used v8086 to run multiple Virtual DOS Machines and had DPMI support in them provided by the VDPMI.SYS virtual device driver.

michaelcampbell 3y ago

> whereas OS/2 was still struggling to run more than one DOS app simultaneously That was hardly universal. I remember running multiple dos-native _games_ on os/2. Yeah, they were slow; they were slow when running under DOS as the only app running, but they ran. I never had any compatibility issues. It was one of the most "fun" OS's I've ever hit.

AtlasBarfed 3y ago

OS/2 needed to be free with enterprise support a paid feature. If IBM did that it would have had a shot. Of course, no way IBM would have done that.