BlasterBoard 2.0 : A modern SB 2.0-compatible ISA sound card

[LABS]

----------------------------

2019-18-02
Thread updated
https://www.vogons.org/viewtopic.php?f=62&t=61098&start=60#p735760

----------------------------

2018-7-09

Hi!

This is a new thread dedicated to my BlasterBoard 2.0 project:
A modern Sound Blaster 2.0-compatible 8-bit ISA sound card for retro PCs.

The prototype looks like this:

It consists of 2 boards: DAC board (left) and OPL2 board (right).
The card supports playback of FM music and digital samples.

At this moment BlasterBoard 2.0 operates as SB2.0 in all DOS applications and games I tested it with.

Here is a short demo:
https://youtu.be/Hrpn6uMCRac

Unlike original SB2.0 card, BlasterBoard has an analog crossfader for manual
adjustment of FM music and digital sample playback levels.

Built on discreet 74HC logic, ATmega328P microcontroller, modern DAC and audio-grade
components in sound path for lowest possible noise and highest audio quality.

Done so far:
- FM music playback as Adlib (0x388) or Sound Blaster (0x2X8)
- 8-bit PCM samples playback in all modes
- Playback frequency from 4KHz to 96KHz

Still to be implemented:
- ADPCM playback
- Handling of sound recording commands (silent output)

[keropi]

very nice! keep up the good work!

[gdjacobs]

Hi!

This is a new thread dedicated to my BlasterBoard 2.0 project:
A modern Sound Blaster 2.0-compatible 8-bit ISA sound card for retro PCs.

The prototype looks like this:

P1010556.JPG

It consists of 2 boards: DAC board (left) and OPL2 board (right).
The card supports playback of FM music and digital samples.

Unlike original SB2.0 card, BlasterBoard has an analog crossfader for manual
adjustment of FM music and digital sample playback levels.

Built on discreet 74HCT logic, ATmega328P microcontroller, modern DAC and audio-grade
components in sound path for lowest possible noise and highest audio quality.

Done so far:
- FM music playback as Adlib (0x388) or Sound Blaster (0x2X8)
- 8-bit PCM samples playback in all modes
- Playback frequency from 4KHz to 96KHz

Still to be implemented:
- ADPCM playback
- Handling of sound recording commands (silent output)

Here is a short demo:
https://youtu.be/Hrpn6uMCRac

At this moment BlasterBoard 2.0 operates as SB2.0 in all DOS applications and games I tested it with.

This is a really great project and has a potential to address one of the fundamental weak points of DOS gaming -- the lack of sound cards without weaknesses.

How much of the bus controller and codec functionality is fixed? Could this base design be expanded to interface via SB Pro, WSS, Ensoniq, and SB16 hardware interfaces, ideally with a second DAC and expanded firmware? Is there enough reserve performance to implement a FIR filter a la the SB16?

[Phreeze]

i will bookmark this thread

[root42]

Awesome project, great results! I am looking forward to the first single board prototype!

[dreamblaster]

great project, if you need any help just pm me

[LABS]

This is a really great project and has a potential to address one of the fundamental weak points of DOS gaming -- the lack of sound cards without weaknesses.

How much of the bus controller and codec functionality is fixed? Could this base design be expanded to interface via SB Pro, WSS, Ensoniq, and SB16 hardware interfaces, ideally with a second DAC and expanded firmware? Is there enough reserve performance to implement a FIR filter a la the SB16?

Thanks, if there will be enough interest in BlasterBoard 2.0, then there will definately be new projects you are talking about

Awesome project, great results! I am looking forward to the first single board prototype!

Single board version will be available very soon, I'm going to make some limited quantity available for purchase, so if you are interested - please let me know.

great project, if you need any help just pm me

Just visited your shop - really great stuff. Thanks for your support and congrats on the 3rd place)

[LABS]

Which games that use ADPCM samples do you know?
Thanks

[derSammler]

Duke Nukem 2, afaik.

[jheronimus]

Can I reserve a card for myself? Will it only be available as a DIY kit, or as a finished product as well?

[keropi]

kinda interested as well - I don't mind to solder my card (prefer it actually) or even anyone else's who cannot solder

[root42]

I am also interested in a card. DIY kit absolutely ok, as long as there aren't any very small SMD parts.

[gdjacobs]

Duke Nukem 2, afaik.

Major Stryker, as well.

[LABS]

Can I reserve a card for myself? Will it only be available as a DIY kit, or as a finished product as well?

kinda interested as well - I don't mind to solder my card (prefer it actually) or even anyone else's who cannot solder

I am also interested in a card. DIY kit absolutely ok, as long as there aren't any very small SMD parts.

You got it. You can have either a kit or I can solder it for you.

[Scali]

Very nice work!
I take it a SB Pro 2 version would not be too far off, now that you've gotten this far.
You'd need to replace the OPL2 with OPL3, and extend the DSP a bit to support stereo samples, and hook up a stereo DAC instead of a mono one, and you'd pretty much be done!

Edit: I do not see mention of any MIDI support. I take it you have not added that functionality to the DSP yet?
I don't see any MIDI/joystick connector on the card either.

[matze79]

i also would like to get a board

Thank you!

[canthearu]

Looks like a fun project. My NEC V30 based computer could use sound blaster.

So count me in ... either as a kit or premade.

[LABS]

i also would like to get a board

Thank you!

Looks like a fun project. My NEC V30 based computer could use sound blaster.

So count me in ... either as a kit or premade.

You got it too.

Very nice work!
I take it a SB Pro 2 version would not be too far off, now that you've gotten this far.
You'd need to replace the OPL2 with OPL3, and extend the DSP a bit to support stereo samples, and hook up a stereo DAC instead of a mono one, and you'd pretty much be done!

Edit: I do not see mention of any MIDI support. I take it you have not added that functionality to the DSP yet?
I don't see any MIDI/joystick connector on the card either.

Theoretically yes. I was thinking about SB Pro at first.
SB Pro has a mixer chip and for full playback emulation it must be implemented. It can be made using dedicated digital pots, but ATmega328P does not have enough free pins to control them. There are other ATmega chips with more pins or interface extender chips, but I want to stick to the most popular and pure ATmega328P and keep the schematics simple.
Ok, even if we skip the mixer chip and mix everything in analog as I already do in my prototype (OPL2 / DAC / CD-In / PC-Speaker - all on dedicated volume pots), there is another issue:
I'm currently implementing 4x oversampling FIR-interpolated DSP algorithm in MCU to eliminate 8-bit quantization noise, now the card has a 12-bit DAC and 8-pole analog Chebyshev LP filter @18kHz. The algorithm is pretty heavy for 8-bit ATmega and will definately not handle 2 streams of SB Pro. So let it better be mono, but upgraded audio signal than usual ringing 8-bit stereo any SB Pro clone out there can provide.

Changing OPL2 to OPL3 requires support for additional SB Pro+ FM registers 2X0-2X3, which will add even more logic ICs. It can be done on PAL or CPLD, but then BlasterBoard 2.0 will loose its simplicity of a DIY soundcard on common components.

Does anyone need a non-MPU-401 MIDI out? Or joystick port? If yes - will take it into account.

If anyone has any more questions or suggestions - please ask.

[matze79]

We also can trade, i can send you a tandy sound board

[root42]

I am totally for a SB2.0 clone at this stage. Keep it simple. Learn from this project, and maybe you can later make a SBPro clone. But with SB2.0 compatibility you will already be able to play virtually all games that support AdLib or SoundBlaster. It is just a matter of fidelity (stereo / 16Bit if going for SB16 compatibilitz) and OPL3 support, which is not even supported by many games.