quick question about 7800 sound chip

[toptenmaterial]

So... does the 7800 use the same chip as the 2600 (POKEY I believe)?

 

Thanks!

[jaybird3rd]

The 2600 used the TIA chip for sound. GCC originally planned to develop a new sound chip ("Gumby") for the 7800, but unfortunately, it was omitted from the final design. The 7800 already included a TIA for backward compatibility with the 2600, so they stuck with the TIA for sound, but they added an audio pin to the cartridge slot so that games which needed better sound could include their own sound chips in the cartridge. Ballblazer and Commando were the only games (released by Atari) which took advantage of this, and both used POKEY chips.

[OldSchoolRetroGamer]

I Googled atari 7800 sound chip and found THIS entry in Wikipedia:

 

Sound

 

A common criticism of the 7800 regards its use of the TIA to provide 2-channel sound effects and music, resulting in sound quality that is virtually identical to the Atari 2600 VCS from 1977. While the inclusion of 2600 hardware is required to maintain compatibility with the older system, this drove up production costs and reduced available space on the 7800’s motherboard. As such, the 7800 does not include additional hardware for generating sound as it does with graphics and the sound hardware is considered the weakest part of the system.

To compensate for this, GCC’s engineers allowed games to include a POKEY audio chip in the cartridge which substantially improved the audio quality. To ensure software developers had an economical means of producing better sound than TIA, GCC had originally planned to make a low-cost, high performance sound chip, GUMBY, which could also be placed in 7800 cartridges to enhance its sound capabilities further. This project was cancelled when Atari was sold to Jack Tramiel.

Despite having the capability to support sound chips in cartridges, almost no 7800 cartridges feature POKEY hardware for enhanced sound. Ballblazer, released in 1987, uses the POKEY to generate all music and sound effects. Similarly, Commando, released in 1989, uses a POKEY to generate in-game music while the TIA generates the game's sound effects for a total of 6 channels of sound.

 

@ jaybird3rd Doh! You JUST beat me to the punch lol!

Edited April 8, 2012 by OldSchoolRetroGamer

[OldSchoolRetroGamer]

Too bad they did not include that pokey sound chip in the console, would have been so much better as every game would have used it.

Edited April 8, 2012 by OldSchoolRetroGamer

[jaybird3rd]

Too bad they did not include that pokey sound chip in the console, would have been so much better as every game would have used it.

Yes. One possible reason (besides the added cost) is that the 7800 is a pretty crowded machine as it is: it includes a 6502, MARIA, TIA, 6532, an OS ROM, and a pair of 2K SRAM chips, all crammed together on a fairly small motherboard.

 

A year or two before the 7800, Mattel had introduced their Intellivision System Changer, a 2600 clone which used the Intellivision for power and A/V output, and which used glop-top chips inside instead of full DIP packages. It might have been nice if Atari had done the same in the 7800, to free up enough board space for a POKEY, but that might not have been feasible at the time.

[mimo]

Another reason is that the 7800 uses a modified 2800 case, so the size of the PCB was limited from the beginning.

Having said that, it is a pretty lame excuse when you look at an rgb 7800 with all the piggy backed daughter boards that they managed to cram under the hood

Edited April 8, 2012 by mimo

[BillyHW]

so that games which needed better sound could include their own sound chips in the cartridge

 

This is so dumb. Which games 'need' better sound? Sound is essential. Every game needs better sound.

[jaybird3rd]

This is so dumb. Which games 'need' better sound? Sound is essential. Every game needs better sound.

That may be true (although I certainly think you could have phrased that more politely), but some games need it more than others. I don't know if POKEY sound would have made a big difference in Asteroids, for example, and there were other 7800 games that I thought made fairly good use of what the TIA could do: I'm sure others feel differently, but I don't have a problem with the TIA sound in Ms. Pac-Man, Dig Dug, and Centipede. Jinks even used it for sound sample playback.

 

Atari probably decided that Ballblazer deserved a POKEY chip because it was already well-known for its music, but there were plenty of other games which also needed it, such as the excruciating Donkey Kong. Having POKEY in the console would have made it available to all the games, which would have been nice, but they had to make an economic decision and it is what it is. Fortunately, the XM module will solve this problem once and for all by adding both a POKEY and a Yamaha YM2151 to the 7800.

[BillyHW]

This is so dumb. Which games 'need' better sound? Sound is essential. Every game needs better sound.

That may be true (although I certainly think you could have phrased that more politely), but some games need it more than others. I don't know if POKEY sound would have made a big difference in Asteroids, for example, and there were other 7800 games that I thought made fairly good use of what the TIA could do: I'm sure others feel differently, but I don't have a problem with the TIA sound in Ms. Pac-Man, Dig Dug, and Centipede. Jinks even used it for sound sample playback.

 

Atari probably decided that Ballblazer deserved a POKEY chip because it was already well-known for its music, but there were plenty of other games which also needed it, such as the excruciating Donkey Kong. Having POKEY in the console would have made it available to all the games, which would have been nice, but they had to make an economic decision and it is what it is. Fortunately, the XM module will solve this problem once and for all by adding both a POKEY and a Yamaha YM2151 to the 7800.

 

I wasn't calling you dumb. I was calling Atari dumb.

 

Just compare the Mega Man 2 sound with the 7800 Donkey Kong. Atari dropped the ball here.

[ApolloBoy]

Just compare the Mega Man 2 sound with the 7800 Donkey Kong. Atari dropped the ball here.

I highly doubt GCC had NES audio in mind when they designed the 7800. That's kind of a flawed comparison anyway as 7800 DK wasn't that good of a port, whereas MM2 is renowned for having some of the best music on the NES.

[toptenmaterial]

This is so dumb. Which games 'need' better sound? Sound is essential. Every game needs better sound.

That may be true (although I certainly think you could have phrased that more politely), but some games need it more than others. I don't know if POKEY sound would have made a big difference in Asteroids, for example, and there were other 7800 games that I thought made fairly good use of what the TIA could do: I'm sure others feel differently, but I don't have a problem with the TIA sound in Ms. Pac-Man, Dig Dug, and Centipede. Jinks even used it for sound sample playback.

 

Atari probably decided that Ballblazer deserved a POKEY chip because it was already well-known for its music, but there were plenty of other games which also needed it, such as the excruciating Donkey Kong. Having POKEY in the console would have made it available to all the games, which would have been nice, but they had to make an economic decision and it is what it is. Fortunately, the XM module will solve this problem once and for all by adding both a POKEY and a Yamaha YM2151 to the 7800.

 

I wasn't calling you dumb. I was calling Atari dumb.

 

Just compare the Mega Man 2 sound with the 7800 Donkey Kong. Atari dropped the ball here.

 

For a more direct comparison, try DK Jr on the NES and 7800. Graphicly they are nearly identical, but the NES version sounds smooth and pleasing to the ear. The 7800 version is brutal!! Nevertheless I do find the sound charming though.

[Lynxpro]

Sorry, I'm going to bump this thread.

 

Was the GUMBY audio chip ever finished? And either way, are there any design specs published? Would it have surpassed Pokey or were they just looking for something that outperformed the TIA on the cheap?

[ColecoGemini]

Speaking of this subject, does anyone here have a schematic for the X-Board mod? I've read that it's pokey method is the same as the XM, but it seems the person who made it doesn't make them any more? I would like to find a way to add pokey sound to my 7800, since sales of the XM have been suspended. I have a copy if Beef Drop and plan to buy DK XM, but I'm not sure if I will ever get an actual XM

 

Thanks!

[Trebor]

Was the GUMBY audio chip ever finished?

 

No...Well, at least not in the sense as a finished product for the 7800. However, since the additional POKEY chip (piggyback) mod for Atari 8bit computers is often referred to as GUMBY sound/GUMBY mod, perhaps something equivalent to two POKEYs (Providing stereo sound) was intended.

 

Some docs here: http://ftp.pigwa.net/stuff/mirror/ftp.spudster.org/pub/Atari/CTH/Text/MODS/

 

Or, it could just be a coincidence.

 

Site that sells the mod to make the dual POKEYs (GUMBY) easy: http://lotharek.pl/product.php?pid=45

 

Here's the schematics:

[Trebor]

Speaking of this subject, does anyone here have a schematic for the X-Board mod? I've read that it's pokey method is the same as the XM, but it seems the person who made it doesn't make them any more? I would like to find a way to add pokey sound to my 7800, since sales of the XM have been suspended. I have a copy if Beef Drop and plan to buy DK XM, but I'm not sure if I will ever get an actual XM

 

Thanks!

It appears you may be able to purchase the XBoard here: http://www.x-game.se/products.htm

 

More specifics on the XBoard here: http://www.x-game.se/products/xboard.htm

 

AFAIK, schematics are not available.

 

Regardless, I do believe you will have ample opportunity to purchase an XM after Curt gets the pre-orders out the door.

 

Pressing forward with the XBoard, if I recall correctly there is a conflict due to the mapping of the extra SRAM of the XBoard which will not allow the XM to functioning properly. So after modifying your system for the XBoard, using it with an XM may not be an option.

[Lynxpro]

It appears you may be able to purchase the XBoard here: http://www.x-game.se/products.htm

 

More specifics on the XBoard here: http://www.x-game.se/products/xboard.htm

 

AFAIK, schematics are not available.

 

Regardless, I do believe you will have ample opportunity to purchase an XM after Curt gets the pre-orders out the door.

 

Pressing forward with the XBoard, if I recall correctly there is a conflict due to the mapping of the extra SRAM of the XBoard which will not allow the XM to functioning properly. So after modifying your system for the XBoard, using it with an XM may not be an option.

 

Holy krap….I didn't know that existed. Why are so many great 7800 mods no longer manufactured when the console is probably at its height of homebrew support?

 

Am I reading correctly that the Xboard had a provision for a secondary Pokey?

 

Just imagine if the conflicts could be fixed and you had an Xboard [w/2 Pokeys], an XM, and a CC2 or its replacement. Quad Pokey madness, a YM2151, 256K RAM [+4K], HSC, and optional SIO support. That would essentially make it the ultimate 8-bit gaming system.

[Rybags]

Since it's been bumped... Pokey could have quite easily have been fit into a smaller DIP by omitting some pins. 40 down to 28 or 24 entirely possible.

 

4 of the POT inputs are unused in most computer applications.

8 pins are dedicated for keyboard scan.

1 of the CS lines could be deleted.

4 pins are dedicated to Serial I/O.

 

The POT lines could have been totally left out although the 2600 method of reading paddles is much more CPU intensive than for Pokey.

[Lynxpro]

Speaking of the XBoard, I wonder if there's a faq of the games that are currently compatible with it. And I'm wondering if the 128K SRAM is system RAM or if its used exclusively for the Pokeys and Maria. From what I've read online, the Pokey hogs the first 16K of RAM on the Commando cart. And who knows how much RAM the Maria can address...