Sound Blaster 1.x with DSP chips from 2.0

[Torinde]

From Sound Blaster 2.0:

Owners of previous revision Sound Blaster boards could upgrade their board by purchasing the V2.00 DSP chip from Creative Labs, and swapping the older DSP V1.0x with the newer replacement. The upgraded board gained the auto-init DMA and new MIDI capabilities of the Sound Blaster 2.0 but not the expanded sampling rates. The upgrade was necessary for full compatibility with the Windows 3.0 Multimedia Extensions upgrade.

Fury3 readme:

Creative Labs Sound Blaster w/2.0 DSP, CT 1320C

So, SB1.5 without C/MS, but with DSP2.0 - probably that's the version emulated in NTVDM as well.

I see a .conf option for C/MS, but not for DSP2.0. Can such be added?

[joncampbell123]

From Sound Blaster 2.0:

Owners of previous revision Sound Blaster boards could upgrade their board by purchasing the V2.00 DSP chip from Creative Labs, and swapping the older DSP V1.0x with the newer replacement. The upgraded board gained the auto-init DMA and new MIDI capabilities of the Sound Blaster 2.0 but not the expanded sampling rates. The upgrade was necessary for full compatibility with the Windows 3.0 Multimedia Extensions upgrade.

Fury3 readme:

Creative Labs Sound Blaster w/2.0 DSP, CT 1320C

So, SB1.5 without C/MS, but with DSP2.0 - probably that's the version emulated in NTVDM as well.

I see a .conf option for C/MS, but not for DSP2.0. Can such be added?

That's what "sbtype=sb2" is for. It's been part of DOSBox since SVN a long time ago. DOSBox-X only refined it's accuracy.

[joncampbell123]

Sound Blaster 2.0 already includes the "high speed" modes for higher sample rates, and that's emulated by DOSBox, including DOSBox-X.

[Torinde]

Yes, yes, I mean the reverse - how to set a configuration matching SB1.x sample rates (lower) with DSP2.0 from SB2.0. Sorry for not being clear enough. Missing combinations in bold?

• SB1.0 = lower sampling rates + C/MS = sb1, cms=auto/on
• SB1.5 = lower sampling rates = sb1, cms=off
• SB2.0 = higher sampling rates + DSP2.0 = sb2, cms=auto/off
• SB2.0 with C/MS = higher sampling rates + C/MS + DSP2.0 = sb2, cms=on
• SB1.0 with DSP2.0 = lower sampling rates + C/MS + DSP2.0 = sb1, cms=on, dsp2=on
• SB1.5 with DSP2.0 = lower sampling rates + DSP2.0 = sb1, cms=off, dsp2=on

[joncampbell123]

You mean a SB 1.x card with a DSP chip replacement to SB 2.0 that can;t do the higher sample rates?

DOSBox and DOSBox-X do not have such an option. But you can emulate a 1.5 card using sbtype=sb1.

Do you need that option?

[joncampbell123]

It's funny you mention that combination by the way. I actually managed to find an SB 1.5 card on eBay, but when I got it, the previous owner had already changed the DSP chip to a 2.0 version. You can tell it's a 1.5 by the CT number and by the fact that if you try to talk to the missing CMS chips the card causes the ISA bus to hang, which was a well known hardware bug with the 1.5 cards.

[Torinde]

You mean a SB 1.x card with a DSP chip replacement to SB 2.0 that can;t do the higher sample rates?
Do you need that option?

Yes - to emulate the earliest Windows sound environment. I was thinking that since all the ingredients are already emulated, and you have the logic for enabling/disabling cms - similar can be applied for dsp2 without major efforts.

If it's too difficult, then feel free to classify my need as just a want :)

[joncampbell123]

I think I can add something like a sbtype=sb1dsp2 for that easy enough. It will emulate sbtype=sb2 but not allow the high speed mode DSP commands. These cards return DSP version 2.0, not 2.01, right?

[joncampbell123]

One more thing. I still have that disassembly of the Sound Blaster DSP as a reference: https://github.com/joncampbell123/sb-firmware

[Torinde]

I don't know, but Wikipedia states "V2.00 DSP".

[rderooy]

Where are you getting SB 1.5/2.0 drivers from for Windows 3.0 Multimedia Edition? The only known OEM releases of that Windows edition (Tandy and Creative Labs), both only support the SB Pro 1.

Or are you instead talking about the Windows 3.0 SB driver package, which is not the same thing. It predates the Windows 3.0 Multimedia Edition release and implements its own proprietary audio API, that only seem to be supported by Creative Labs own mixer and sound player that are part of the driver package (there may have been some other niece software, but I could not quickly find any).

[joncampbell123]

Also the Windows 3.0 Multimedia Edition sound drivers are terrible when it comes to asking for the playback position. I wrote a sort of media player for DOS/Windows 3.x/95 that plays WAV files. It's quite good at timing in Windows 3.1 and higher but the Windows 3.0 setup gives poor quality timestamps.

[Torinde]

I'm planning to test those, but haven't yet. I checked Wikipedia edit history and there's no link (edit is from IP user in 2015, so unlikely to get a Talk page message today).

Win3.0 Creative drivers - here someone mentions that those maybe used an "early form of MCI/WinMM API".

This kind of mixes the two topics:

• "in November 1990, Microsoft recommended that developers use the Sound Blaster, the only existing sound card that came close to matching the MPC specs. In fact, it seemed at the time that Microsoft had simply taken the Sound Blaster specs and added an audio mixer"
• "Sound Blaster Pro ... adds the audio] mixer necessary to meet the MPC standard fully"

SB2.0, SB Pro, Win3.0MME were all released around the same time.

Maybe SB1.x drivers from a Win3.1 beta will work in 3.0MME (with some implanted system files, if needed).

Finally, WinWorld has PC-9801 MME edition (and 3.0b non-MME), I don't know what sound devices did it support.

[joncampbell123]

Latest commit: use sbtype=sb2.0 for DSP 2.00 (not 2.01) emulation. It's sb2 emulation but the high-speed DSP commands are disabled.

For good measure, even though there's no change in emulation aside from the returned DSP version, there is also a sbtype=sb1.0

[Torinde]

Great, thank you @joncampbell123 !