3 ms·

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 righ

by 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.

rasz 3y ago
> especially audio stuff. https://news.ycombinator.com/item?id=35919612 https://news.ycombinator.com/item?id=35919612 tldr: https://devblogs.microsoft.com/oldnewthing/20160411-00/?p=93281 https://devblogs.microsoft.com/oldnewthing/20160411-00/?p=93... Intel screwed up implementing v86 mode by missing one privileged accesses trap - Protected Mode program (CPL 3) executing CLI and expecting POPF to restore interrupt flag. CLI will correctly trap, but POPF is silently ignored AND doesnt trap. No easy workarounds available.
- rep_lodsb 3y ago
  That's in protected mode. In V86 with IOPL < 3, both PUSHF and POPF will trap. However I think some versions of Windows used to run V86 code with IOPL = 3. At least I remember being able to run "CLI, HLT" instructions in DEBUG inside a DOS box and locking up the entire system.
  - rasz 3y ago
    Yes, you are right, sorry. Should be "Intel screwed up implementing Protected Mode by missing one privileged accesses trap - Protected Mode program (CPL 3, IOPL < 3) executing CLI and expecting POPF to restore interrupt flag. CLI will correctly trap, but POPF is silently ignored AND doesnt trap. No easy workarounds available." One of the prominent victims is Doom. Works in Windows only due to hacks.
justsomehnguy 3y ago
You probably miss what you can jump from Win95/98 to the 'pure' DOS seamlessly, while with OS/2 HPFS' you ..

by bane 3y ago

rasz 3y ago

> especially audio stuff. https://news.ycombinator.com/item?id=35919612 https://news.ycombinator.com/item?id=35919612 tldr: https://devblogs.microsoft.com/oldnewthing/20160411-00/?p=93281 https://devblogs.microsoft.com/oldnewthing/20160411-00/?p=93... Intel screwed up implementing v86 mode by missing one privileged accesses trap - Protected Mode program (CPL 3) executing CLI and expecting POPF to restore interrupt flag. CLI will correctly trap, but POPF is silently ignored AND doesnt trap. No easy workarounds available.

rep_lodsb 3y ago
That's in protected mode. In V86 with IOPL < 3, both PUSHF and POPF will trap. However I think some versions of Windows used to run V86 code with IOPL = 3. At least I remember being able to run "CLI, HLT" instructions in DEBUG inside a DOS box and locking up the entire system.
- rasz 3y ago
  Yes, you are right, sorry. Should be "Intel screwed up implementing Protected Mode by missing one privileged accesses trap - Protected Mode program (CPL 3, IOPL < 3) executing CLI and expecting POPF to restore interrupt flag. CLI will correctly trap, but POPF is silently ignored AND doesnt trap. No easy workarounds available." One of the prominent victims is Doom. Works in Windows only due to hacks.

justsomehnguy 3y ago

You probably miss what you can jump from Win95/98 to the 'pure' DOS seamlessly, while with OS/2 HPFS' you ..