DOS ain't dead - Waiting for 3 (or 3.3) microseconds? 286 and up.

Waiting for 3 (or 3.3) microseconds? 286 and up. (Developers)

posted by myrkraverk, 13.12.2012, 14:07

Please excuse the late reply.

> Is this meant to be widely deployed? I mean, are there real machines that
> will be running this? SoundBlaster is quite rare on actual hardware these
> days except on old machines.

While I'm playing with DOSBox, the code is meant to run on actual hardware too. My previous code examples has been tried with success on actual hardware, both with FreeDOS and a DOS window in OS/2. Some of that was, I believe, hardware emulating the Sound Blaster though.

I've heard there are threads on the fasm forums where people are complaining about DOS software not working in real DOS. I'd rather avoid that trap.

> I think SoundBlaster is dead, I don't think (m)any people will use it.
> Sure, it's well-documented, even fun (I guess, never tried) to program for
> it, but it's fairly useless. Not trying to discourage you, just being
> realistic. :-/

My [possibly false] supposition is that there are still quite a lot of systems with Sound Blaster emulation out there.

> I'm still not sure if you intend this to work on real hardware (actual
> 286?) or just anything you can find (DOSBox). For instance, I don't think
> WinXP supports int 15h, 86h very well. And of course DOSBox isn't accurate
> timings at all. I think every instruction in DOSBox takes only a single
> (virtual) clock cycle. So it's not reliable for timings (and only simulates
> a fast 486 or slow 586, at best).

Yes, I do want this to work on real hardware.

> As for a delay, not sure, but I'm naively guessing a slow DIV instruction
> or two would be good enough. Heck, even the 386, at fastest, could only do
> a single instruction in two clocks, so the 286 must be easier to write
> slowdown routines. But if you are targeting both real 286s, DOSBox, and
> modern 4 Ghz AMD64-capable machines, you're probably asking a bit too much.

There are code examples that may work out. I must confess I've yet to give the solutions I've got a try.

[thanks to everyone who replied]

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Complete thread:

Waiting for 3 (or 3.3) microseconds? 286 and up. - myrkraverk, 09.12.2012, 23:41 (Developers)
- Waiting for 3 (or 3.3) microseconds? 286 and up. - RayeR, 10.12.2012, 03:09
- Waiting for 3 (or 3.3) microseconds? 286 and up. - Japheth, 10.12.2012, 11:42
  - Waiting for 3 (or 3.3) microseconds? 286 and up. - RayeR, 10.12.2012, 18:04
- Waiting for 3 (or 3.3) microseconds? 286 and up. - bretjohn, 10.12.2012, 15:52
  - Waiting for 3 (or 3.3) microseconds? 286 and up. - myrkraverk, 10.12.2012, 21:22
- Waiting for 3 (or 3.3) microseconds? 286 and up. - myrkraverk, 10.12.2012, 21:16
- Waiting for 3 (or 3.3) microseconds? 286 and up. - Rugxulo, 10.12.2012, 22:03
  - Waiting for 3 (or 3.3) microseconds? 286 and up. - myrkraverk, 13.12.2012, 14:07
    - Waiting for 3 (or 3.3) microseconds? 286 and up. - marcov, 13.12.2012, 22:51
      - Waiting for 3 (or 3.3) microseconds? 286 and up. - RayeR, 14.12.2012, 01:12