DOS ain't dead - vsbhda - BOOST demo with SB Live

vsbhda - BOOST demo with SB Live (Users)

posted by Japheth , Germany (South), 20.11.2025, 11:24

> So I tried to set 1Ah after VSBHDA loaded but ...

Value 0x1A is inherited from mpxplay and has its origin in EMU10K1.H:
#define TIMER_RATE_MASK 0x000003ff /* Timer interrupt rate in sample periods */ /* 0 == 1024 periods, [1..4] are not useful */ #define TIMER_RATE 0x0a00001a
Both use the TIMER_RATE value to write to the "timer" port. It's a dword, so outl() is used for writing. However, the port has WORD size only; at offset 0x1C there's the AC'97 data port, so the outl() writes 0xa00 to that port, which seems pretty hazardous and "buggy" to me (constant TIMER_RATE has vanished in current emu10k1.h in Linux ).

> I have to lower the value to 1-3 to get smooth playback for
> Boost demo and value 1 for another demo Dream by Peon (compiled with DJGPP,

As you can see from the comment in emu10k1.h, those values are "not useful". :-D

> I dumped the regs with your SBLIVE.EXE tool
> and there are many more differences between VSBHDA and SBEMU initialisation
> values

Yes. There's a bug in sbemu, however, making it skip every second entry in the microcode array during initialization ( each entry is 64-bit ).

> (I pressed the reset button between making second dump).

I've got the impression that most EMU10K1 register values are not affected by reset, and there's no software reset either...

---
MS-DOS forever!

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Complete thread:

Jemm386 5.86 is great! - Laaca, 11.11.2025, 20:41 (Users)
- Jemm386 5.86 is great! - Japheth, 12.11.2025, 07:19
  - Jemm386 5.86 is great! - RayeR, 12.11.2025, 15:28
    - Jemm386 5.86 is great! - Japheth, 12.11.2025, 18:34
      - VSBHDA is also great (was: Jemm386 5.86 is great!)! - SuperIlu, 12.11.2025, 22:48
      - Jemm386 5.86 is great! - RayeR, 13.11.2025, 16:22
        Jemm386 5.86 is great! - rr, 14.11.2025, 06:46
        Jemm386 5.86 is great! - Japheth, 14.11.2025, 08:35
        Jemm386 5.86 is great! - RayeR, 15.11.2025, 04:15
        Jemm386 5.86 is great! - Japheth, 15.11.2025, 09:02
        Jemm386 5.86 is great! - RayeR, 18.11.2025, 06:03
        Jemm386 5.86 is great! - Japheth, 18.11.2025, 12:41
        Jemm386 5.86 is great! - RayeR, 18.11.2025, 23:23
        vsbhda - BOOST demo with SB Live - Japheth, 19.11.2025, 09:40
        vsbhda - BOOST demo with SB Live - RayeR, 20.11.2025, 06:05
        vsbhda - BOOST demo with SB Live - Japheth, 20.11.2025, 11:24
        vsbhda - BOOST demo with SB Live - RayeR, 22.11.2025, 04:39
        vsbhda - BOOST demo with SB Live - Japheth, 22.11.2025, 18:20
        Jemm386 5.86 is great! - rr, 18.11.2025, 19:08
        Jemm386 5.86 is great! - RayeR, 18.11.2025, 23:24
  - Jemm386 5.86 is great! - Laaca, 12.11.2025, 22:41
    - Jemm386 5.86 is great! - Japheth, 13.11.2025, 04:23