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Better sound in 7800 games

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I noticed in the Beef Drop thread there was talk of using Pokey sound, but that would require cannibalising Ballblazer carts for chips. Well, is there any reason why the sound chip HAS to be pokey? Couldn't a cart PCB be made up for other sound chips? What about that chip used in the AtariVox? Couldn't that be placed inside a 7800 cart? Surely there must be low cost sythesizer chips that could be used?

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Actually, having thought about this some more... the 2600 AtariVox would probably work as-is with the 7800.. just plug it in... but a 7800 AtariVox could be made that attached as a pass-through cartridge. The advantage being that the AtariVox sound would be mixed with the ordinary TIA sound. Also, it could provide 7800 high score cartridge emulation as well as general purpose flash rom.

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I won't worry too much about Pokey chips drying up. Best still sells them for $5 a piece and O'Shea's is still sitting on thousands of boxed Ballblazers which are also $5 each.

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but it would be cool to see an atari 7800 cart with, say, an OPL2.

 

sounds imo way cooler than the pokey.

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People here have played Jinx, right? As far as I know, those are the sounds of the 7800 hardware (TIA/MARIA) with no help from a POKEY at all. There are both voice and synth sounds in that game (sort of like "QUADRUN, QUADRUN, QUADRUN!!"). This is a perfect example of enhanced 7800 sound and it really demonstrates what the 7800 is capable of in terms of making these types of sounds. Some one needs to analyze the Jinx binary and figure out what Atari did to put these sounds on this game with out using a POKEY or any other chip in the cartridge technique. Future 7800 homebrews are sure to be truly amazing if someone can figure this out and incorporate this technique into the games. :idea: :!:

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Well, Jinx does have an extra 8K of RAM onboard, that probably helps a bit. :)

 

Mitch

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I'm not sure about the actual gameplay, but the Jinks title screen apparently plays digital samples for the music. The title music only plays when nothing is happening on the screen. Honestly I think you can play PCM on pretty much anything, the problem is it eats all your cpu time so its pretty useless in most cases.

 

I agree that Ballblazer is probably in abundant supply. But for larger games that need bankswitching, the only option for POKEYs is Commando and I'm not sure that's as easy to get in quantity.

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I noticed in the Beef Drop thread there was talk of using Pokey sound, but that would require cannibalising Ballblazer carts for chips. Well, is there any reason why the sound chip HAS to be pokey? Couldn't a cart PCB be made up for other sound chips? What about that chip used in the AtariVox? Couldn't that be placed inside a 7800 cart? Surely there must be low cost sythesizer chips that could be used?

 

It would be nice if there was a new PCB developed. If that happens, then yeah you might as well support a different sound chip, though many might prefer the authenticity of pokey. I think the developer of the AtariVox said that the Speakjet chips cost $25 each, so it sounds too pricy for inclusion in a cart.

 

I posted about an interesting non-pokey chip a while back in the hardware forum. I'm not sure the hardware guys found it very interesting, but for what its worth, here's an edited copy:

 

There is a cost-reduced version of the OPL2 called the YM2413B. It's an 18-pin chip with an analog output, and runs on 5V, but it apparently expects a 3.58MHz clock signal. That's double the 7800 clock signal. I wonder if the half speed clock can be worked around through software, or if it would be impossible to make it sound right. Also, it appears from some web sites that this chip is only available in quantities of 1000, and I didn't find any resellers that list prices. So I have no idea how expensive it is. I believe it was used as a sound enhancement in some non-US Sega Master Systems. It's not the standard SMS chip, its better than that.

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I noticed in the Beef Drop thread there was talk of using Pokey sound, but that would require cannibalising Ballblazer carts for chips. Well, is there any reason why the sound chip HAS to be pokey? Couldn't a cart PCB be made up for other sound chips? What about that chip used in the AtariVox? Couldn't that be placed inside a 7800 cart? Surely there must be low cost sythesizer chips that could be used?

 

I think the "Yamaha 2151 or any of the OPL series" would be

perfect for the 7800. Before I knew the history of the 7800 I use

to try and compare the 7800 with the "Atari System 1" arcade

board as a means of trying to link the both the systems. I always

thought that Atari was trying to bring the "Arcades" of that era

to the 7800 home console. Seeing an actual Atari System 1 up

close, those things are really big... But yea; I think the Yamaha

OPL series might be ideal for the 7800. :)

 

 

http://www.system16.com/atari/hrdw_system1.html

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I have thought about including CEM3394, SN76477, and SN76496 chips in specialized carts, but doubt that those chips are still in production; don't know where to buy them; and producing compatible PCBs would be costly.

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