Just installed Windows 98 and on the first startup heard a "Start Windows" sound))) What a bliss!))) Should I rename it to a "Bliss Board 2.0"? )) Did not expect that actually) Windows autodetected it during setup as a Sound Blaster or compatible 😎 So it is officially SB-compatible now 😊
Would it be hard to implement a digital out? Maybe just as a header on the board? I know it's not really necessary for the kind of tech we are dealing with but I'm still interested in how much audio quality one can get out of such a chip using a big homping hifi amp 😀
Would it be hard to implement a digital out? Maybe just as a header on the board? I know it's not really necessary for the kind of tech we are dealing with but I'm still interested in how much audio quality one can get out of such a chip using a big homping hifi amp 😀
The OPL has digital output that gets converted by a Yamaha DAC. I guess you would need a custom resampling chip to make the output compatible with digital out like SPDIF or similar. Plus you would need digitial mixing of the SB DSP stuff...
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Would it be hard to implement a digital out? Maybe just as a header on the board? I know it's not really necessary for the kind of tech we are dealing with but I'm still interested in how much audio quality one can get out of such a chip using a big homping hifi amp 😀
The OPL has digital output that gets converted by a Yamaha DAC. I guess you would need a custom resampling chip to make the output compatible with digital out like SPDIF or similar. Plus you would need digitial mixing of the SB DSP stuff...
Right, OPL2's digital output is a weird 16-bit floating point (13.3) @ 49716Hz and ATmega's output to DAC is SPI using 16-bit data words (12 bits for sample + 4 bits for data) @ 4x of playback sample rate.
I finally finished the prototype!
Now it has completely new mixer, output filter and noiseless power supply (breadboard on the left).
The card has 4 sound sources:
1) An 8-bit mono sample playback channel, which is fully compatible with SB 2.0 API, ThunderBoard API and has some extra functions for generating test waveforms and data logging for firmware debugging etc. Available I/O ports are: 0x200, 0x220, 0x240, 0x260, 0x280, 0x2A0, 0x2C0, 0x2E0 (jumper-selected). IRQs: 3/5/7, DMAs: 1/3
2) An OPL2 FM synth accessible via 0x2X8/0x2X9 ports or 0x388/0x389 ports, has dedicated IRQ selection jumper for extra 2 timers available on YM3812 chip.
3) PC-speaker input, so games like Ultima 6, which support OPL2 music and PC-speaker sound effects can be played on the same speakers.
4) CD input for games with CD soundtrack.
Each of these 4 channels has a dedicated volume pot.
The mixer is built on 3 TL074 opamps, has hardcore power filtering and is dead quiet even on a breadboard with all that wires hanging around. The biggest challenge that took more than a month was to make it so quiet and transparent. It has a signal-to-noise ratio superior to the CD output's 96dB (the highest quality sound source of all 4), so there is simply no need for better noise floor audio path for these sources.
Tested the card on all my PCs with ISA slots: 386/25, 486/33, P166 MMX, P3-1GHz. And it works smooth, no clicks, no noise. CD, samples, OPL2, PC speaker - all I wanted to have sounds amazing.
My goal was to make for myself the best sounding, the simplest possible, affordable and the most DOS games compatible sound card.. and I finally made it 😎
Now it is time to assemble it on a normal PCB.
If anyone is still interested in building one for yourself, I will be selling PCBs soon with all components included as a kit or I could solder it for anyone for some extra.
The firmware will be open-source as soon as PCB tests will be completed, so there will be a room for experiments and custom firmwares.
Tracing in progress
PS:
I already tested BlasterBoard with games Doom/Doom2/Quake/Descent/Descent2/Dune/Duke Nukem 3D/Duke Nukem 2/System Shock/Heretic/Hexen/Hexen 2 (Windows 98)/Beneath the Steel Sky/Full Throttle/Gabriel Knight/Secret of Monkey Island/Blood/Inherit the Earth: Quest for the Orb/Command & Conquer/Dreamweb/Warcraft/Warcraft 2/Prince of Persia/Ulitma 6... trackers Impulse Tracker/Scream Tracker/Fast Tracker/Cubic Player/Edlib/RAD/SAT/Adplay... all worked fine. Can anyone come up with any game or app or demo with issues where I can test the card? I also already tried to set it up under Linux and BSDs. All worked fine.
Thanks.
Last edited by LABS on 2018-09-25, 08:39. Edited 1 time in total.
Regarding tests: demo scene productions might be worth a try. Like Panic, Second Reality and the like. But if Screamtracker works, they will probably work as well.
Did you try Windows 3.x?
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Regarding tests: demo scene productions might be worth a try. Like Panic, Second Reality and the like. But if Screamtracker works, they will probably work as well.
Did you try Windows 3.x?
Yes, I should definately try more demos and Win 3.1. Win 98 however works fine. But just tried Diablo which use DirectX SB driver and it has some issues. It plays fine overall, but when the sound engine stops during level loading and starts again - it plays last sound buffer once again with old sound data, then it makes short noise and then plays new data normally. That is a firmware issue, so need to dive deeper into this later.
A few more question: what quality will the PCB be? Tin or gold plating? What solder stop? How much copper?
Can you estimate a price? I guess you will make at least 10 kits.
Yellow soldermask and ENIG surface finish. Estimation is very rough so it is too early to say - it has a lot of components and everything is THT, but I will make it as reasonable as possible.
Hey guys,
can anyone check please if Impulse Tracker 2.14 makes a single click on startup screen with SB 2.0 or any other old SB? I have a click and I logged it's communication with the card and found nothing fancy there - usual DSP resets, set time constant (0x40), turn speaker on (0xD1), set DMA buffer's length (0x48) and start high-speed DMA auto-init transfer (0x90). No other game/tracker clicks during sound startup/autodetection etc, only IT. Can't understand is it me or is it IT?
Thanks a lot.