Raven. A homemade Atari-like computer

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agranlund
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Re: Raven. A homemade Atari-like computer

Post by agranlund »

Oldskool wrote: Mon Apr 29, 2024 6:40 pm Can send you free of charge 2 x Picogus pcb v1 (very diy friendly). Almost the same functionality as the v2 but you can use a picopi.
Also can include a snarkbarker pcb which is a sb1 clone (1 to 1) with about 60% of the parts.
Both are open source.
Thank you for the offer, that is super generous of you!
I don't think it's necessary though, the picogus Tindie store claims they will be ready in early May and I have plenty of other things to keep me occupied in the meanwhile :)

Oldskool wrote: Mon Apr 29, 2024 6:40 pm One of the drawbacks for the picogus could be:
PicoGUS requires an ISA bus speed of 8.33MHz or lower. Glitchy playback or silence may happen at higher bus speeds. Also compatibility with different chipsets may vary, specifically for DMA.
Ah that's good to know! I can talk slowly to it, it's not that much data being transferred after all.

I don't actually have ISA-DMA support. I knew going in that would be a problem for Soundblaster specifically, but figured I'll just get this up and running and experiment with audio when the time comes (ie; now :) )
Worst case, there was always a fallback plan of making some kind of covox-inspired ISA card, maybe with FIFO and IRQ so it wouldn't have to be such a cpu hog - hmmn, like the Disney Sound Source now that I think about it.

But reading up on GUS, it feels like a perfect solution.
If I understand correctly those cards always hardware-mix and play from on-board soundcard RAM, and you can upload to that via DMA or PIO as you choose. That should slot in neatly with Atari xbios sound I think (and give 15 additional HW channels as a neat bonus)

I see there is a new GUS replica card available as well. Much more expensive of course and not as flexible as picogus but I can see why purists would maybe want a hardware clone over emulation.
Oldskool
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Re: Raven. A homemade Atari-like computer

Post by Oldskool »

agranlund wrote: Tue Apr 30, 2024 1:47 pm
Thank you for the offer, that is super generous of you!
I don't think it's necessary though, the picogus Tindie store claims they will be ready in early May and I have plenty of other things to keep me occupied in the meanwhile :)

But reading up on GUS, it feels like a perfect solution.
If I understand correctly those cards always hardware-mix and play from on-board soundcard RAM, and you can upload to that via DMA or PIO as you choose. That should slot in neatly with Atari xbios sound I think (and give 15 additional HW channels as a neat bonus)

I see there is a new GUS replica card available as well. Much more expensive of course and not as flexible as picogus but I can see why purists would maybe want a hardware clone over emulation.
No Problem. Tried to buy a V2 last time but they were gone in a couple of hours so was just a bit too late.
If you can't get one let me know. V1 one is not a lot of soldering. Snarkbarker is another story...
Also build a GUS replica however I think that all AMD Interwave chips are gone now (mostly). So I'm not sure if that is still an option. However a guy in Sweden seems to be selling these. Amd Interwave based ones are not fully compatible with the older ones however these have much more memory 16mb vs 1mb.
If you can get the GUS going that is like the ultimate solution. Indeed plays samples from it's own memory and does hardware mixing (a bit a Paula on steroids).

You already have probably found these (unofficial programming guide)

https://www.phatcode.net/articles.php?id=229

Official programming guide

http://archive.gamedev.net/archive/refe ... le448.html
Atarian Computing
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Re: Raven. A homemade Atari-like computer

Post by Atarian Computing »

@agranlund

Holy moly, man! Nice one! I am so building this. At one point, I was so desperate for a TOS clone that I was going to re-create the Milan with a 060 socket. I got part of the routing done and ran outta steam.

Btw, you mention Mach32 but shouldn't Mach64 work as well? Should be faster like it is in my TT.

Josh.
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agranlund
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Re: Raven. A homemade Atari-like computer

Post by agranlund »

Oldskool wrote: Tue Apr 30, 2024 2:44 pm You already have probably found these (unofficial programming guide)

https://www.phatcode.net/articles.php?id=229

Official programming guide
http://archive.gamedev.net/archive/refe ... le448.html
Nice! I had found one of them but the other link was new to me. Good stuff :)
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agranlund
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Re: Raven. A homemade Atari-like computer

Post by agranlund »

Atarian Computing wrote: Thu May 02, 2024 10:35 am Btw, you mention Mach32 but shouldn't Mach64 work as well? Should be faster like it is in my TT.
Josh.
I'm using the regular TT drivers so can't see a reason why the Mach64 couldn't be made to work too, I was only able to find the M32 for a decent price.
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agranlund
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Re: Raven. A homemade Atari-like computer

Post by agranlund »

Finally got around to testing that Midi works as expected, at least the -out part of it :)
The Mac is acting as a very expensive MT32 synth for it.



Raven does not have any ACIAs so Midi rx/tx is going through the second MFP.
Things which use the bios for Midi should work but not things which tries to hit the non-existing ACIA directly.
(I will need to port the Vampire's MROS driver for Cubase to work)

There's some kind of embryo of a general Audio system in the works.
It was mainly meant for handling PCM devices but now that I got sidetracked into thinking about Midi I realise it probably makes sense for that system to also do some Midi stuff. It does make sense if the same audio device driver is able to handle either or both PCM and Midi.
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Cyprian
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Re: Raven. A homemade Atari-like computer

Post by Cyprian »

agranlund wrote: Sat May 04, 2024 7:11 pm Raven does not have any ACIAs so Midi rx/tx is going through the second MFP.
Things which use the bios for Midi should work but not things which tries to hit the non-existing ACIA directly.
(I will need to port the Vampire's MROS driver for Cubase to work)
there you can find MROS driver source code
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peters
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Re: Raven. A homemade Atari-like computer

Post by peters »

Fantastic, is that a bit of Rick Wakeman ?
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dhedberg
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Re: Raven. A homemade Atari-like computer

Post by dhedberg »

Oh my! This is such an amazing achivement! :shock:
I want one! I neeeed one! :D
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peters
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Re: Raven. A homemade Atari-like computer

Post by peters »

This is an amazing project. The coremark is similar to the Milan with 060 but it looks faster.

The ability to run ST games makes it very interesting, something my Milan can't do. Has any 040/060 clone ever done that ? Could your CaSTaway work on the Milan ?

Your project, your rules. I would have put cheap 1Gb memory card slots in it and some pci slots but that would have meant a bigger board.

Ps.
My idea didn't get a lot of traction, even in 2018
https://www.atari-forum.com/viewtopic.p ... rs#p336996
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