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Matej

Quadro Pokey PCB (4x for TMC2)

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Before people launch off into featureville (stereo, quad, kitchen sink, ect.), I think an 'exact' drop-in replacement for the 'original' Pokey would be a fantastic idea since the individual price has gone up to $20 a pop from BEST Electronics, and he limits you to one per order. And yes a stereo or quad version would also be a great addition, but I don't think it should come as a sacrifice to people who still need an original Pokey replacement. However if one device can can serve all instances so much the better.

 

- Michael

 

Fred Quimby (batari), he of Harmony Cartridge and Harmony Encore Cartridge fame, showed a work-in-progress 40-pin DIP mounted ARM-based implementation of POKEY's sound generation capabilities called - fittingly enough - 'HOKEY." That was roughly 3 years ago. We have seen little about it in at least 2 years. This kind of thing, more than a "full" POKEY, is needed to keep the hobby viable - every HOKEY or equivalent in use for 7800 game cartridges will save a genuine POKEY for vintage A8 machines, 5200's and original Commando/Ballblazer cartridges and arcade machines. Such a limited sound-generator device would also help those who just want to make music - I mean, do all those stereo and quad-POKEY mods really need to run 2 or 4 separate keyboards, SIO interfaces and paddle sets? Of course not. One "full" POKEY and 3 HOKEY-like chips would give amazing audio possibilities without sacrificing vintage hardware.

 

Al has been cautiously optimistic about HOKEY in the few times it comes up in connection with 7800 homebrew carts - hopefully that means it might actually happen. If so, Fred could have a new customer base in A8 owners who want to do these advanced audio mods as well.

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Fred Quimby (batari), he of Harmony Cartridge and Harmony Encore Cartridge fame, showed a work-in-progress 40-pin DIP mounted ARM-based implementation of POKEY's sound generation capabilities called - fittingly enough - 'HOKEY." That was roughly 3 years ago. We have seen little about it in at least 2 years. This kind of thing, more than a "full" POKEY, is needed to keep the hobby viable - every HOKEY or equivalent in use for 7800 game cartridges will save a genuine POKEY for vintage A8 machines, 5200's and original Commando/Ballblazer cartridges and arcade machines. Such a limited sound-generator device would also help those who just want to make music - I mean, do all those stereo and quad-POKEY mods really need to run 2 or 4 separate keyboards, SIO interfaces and paddle sets? Of course not. One "full" POKEY and 3 HOKEY-like chips would give amazing audio possibilities without sacrificing vintage hardware.

 

Al has been cautiously optimistic about HOKEY in the few times it comes up in connection with 7800 homebrew carts - hopefully that means it might actually happen. If so, Fred could have a new customer base in A8 owners who want to do these advanced audio mods as well.

 

Agreed... just the sound capabilities would be good for the dual Pokey upgrades or 7800 carts. But my concern whenever I see talks like this about creating some new version of something, is that it gets mired down by all the feature requests. Case in point, why did it take so long for a new A8 motherboard to appear, or for that matter where is this fabled Hokey? Problem is that people want it all, and many times this mentality ends up killing the project all together.

 

Just my 2 cents ;)

 

- Michael

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Agreed... just the sound capabilities would be good for the dual Pokey upgrades or 7800 carts. But my concern whenever I see talks like this about creating some new version of something, is that it gets mired down by all the feature requests. Case in point, why did it take so long for a new A8 motherboard to appear, or for that matter where is this fabled Hokey? Problem is that people want it all, and many times this mentality ends up killing the project all together.

 

Just my 2 cents ;)

 

This is why I am a big believer in keeping the development of these retro hobby projects open. I know people would like to be compensated for their time and thus tend to keep their projects closed, but I wish people would truly consider the greater good and think of the reality of the tiny market that the retrocomputing hobby represents. Maybe I just have the benefit of a day job that pays me well that I can give away my 'free time' projects without worry, but I think it also comes down to putting a higher value on the community than the few bucks I might make if I kept a design closed.

 

We're all doing this in our spare time, and it's inevitable that people's priorities can change. It's really a bummer when a promising project pops up, but vanishes when the original developer has conflicts with real life or their interests shift to something they find more challenging or exciting. Open projects can be adopted and picked up and can live on when this perfectly understandable situation happens. Closed projects die on the vine and everyone suffers yet another round of getting their hopes up and then getting disappointed.

 

Some kind of mutually agreed upon royalty scheme could help solve both problems. We have people that are good developers (hw and sw), and people that are good at production of an existing design. The skills and drive needed to do both aspects well are rare to find in one person, so a more symbiotic and fair approach would be really nice to see. Open projects, designed by the people good at designing, manufactured by the people good at manufacturing, and profits shared fairly [edit: no, I don't have a great idea of how to make this entirely fair if an 'open' project is abandoned by an original developer and later picked up by one or more people...]

 

Just adding two more cents to the pile!

Edited by TangentAudio
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Hello guys

 

ABBUC did support a few hardware product developments money wise. IIRC the TurboFreezer 2011 was one of them. Maybe you guys could/should contact Wolfgang (our president).

 

Sincerely

 

Mathy

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Hello guys

 

 

I mean, do all those stereo and quad-POKEY mods really need to run 2 or 4 separate keyboards, SIO interfaces and paddle sets? Of course not. One "full" POKEY and 3 HOKEY-like chips would give amazing audio possibilities without sacrificing vintage hardware.

 

Two separate keyboards and two SIO interfaces might be nice to have. Let's keep those (in both stereo and quad-POKEYs), but one Pokey can already handle eight paddle, that should be enough. IMHO the stereo-POKEY should have two complete POKEYs in one case (except maybe for the paddle inputs on the second POKEY) while the quad-POKEY would also only have two full POKEYs inside and two "sound only" POKEYs. And of course the stereo-POKEY should have two sound output pins and the quad-POKEY should have four.

 

Sincerely

 

Mathy

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QuadPokey and OctaPokey boards are testing now.Name will be PokeySonic 4 and Pokeysonic 8.They will have covox too and gtia playback into audio out cinch too...

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And I weep for the 7800 home brew carts that could have been ... and the broken A8 machines and 5200's and arcade boards ... *sigh*

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I really think this project should be based upon a custom FPGA (or CPLD) version of a Quad (or more) channel Pokey. Because like DrVenkman so appropriately pointed out real Pokey's are a rare breed. Using 4 or worse yet 8 for just one machine will quickly eat up what chips are left. Just a thought ;)

 

- Michael

Edited by mytekcontrols
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Hello Matej

 

Do you have any pictures of the boards?

 

Sincerely

 

Mathy

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I will post official announcement (photos, videos etc) when HW developer will finish tests and board design.

First there will be boards using real Pokeys after that there will be also version with 4x / 8x Pokey inside FPGA or MCU...

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In my arcade PCB closet, I have a Major Havoc PCB as well as a few Star Wars PCBs. I have verified in the arcade ROM disassembly that the addresses of each POKEY are at steps of 0x, 1x, 2x, and 3x. I see that a POKEY and a QUAD POKEY are both 40 pin chips, but have yet to find the arcade PCB schematics to verify that they are pin compatible (which implies mono sound).

If someone is motivated enough to track down evidence of pin compatibility and to create something decent in TMC2 Tracker or otherwise, I'll make the effort to pull the chip from a board, plug it in to my "daily-driver" 130XE (or other machine if not socketed), try it out, and record/share a video.

This offer is time-limited, so if you or someone else is reading this in 2020+, it may be too late. icon_smile.gif

Edited by jmccorm
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I surely hope that if a quad board is made for the A8's, that it isn't based on individual Pokey chips. Definitely need to go with an FPGA Quad version instead, and patterning that off of an original quad Pokey chip would seem like a good way to go, since I'm sure the arcade people would appreciate that as well.

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Quad Pokey is not pin compatible with ordinary Pokey. It has four separate audio outputs, additional chip select inputs and relies on external logic to generate chip select signals.

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I surely hope that if a quad board is made for the A8's, that it isn't based on individual Pokey chips. Definitely need to go with an FPGA Quad version instead, and patterning that off of an original quad Pokey chip would seem like a good way to go, since I'm sure the arcade people would appreciate that as well.

Was googling for the pinout and noticed that a quad pokey fpga board exists: https://hotrodarcade.com/products/new-atari-quad-pokey-eliminator-replacement-board

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Quad Pokey is not pin compatible with ordinary Pokey. It has four separate audio outputs, additional chip select inputs and relies on external logic to generate chip select signals.

 

Although it would be nice if it was a drop-in, it's probably better in this form since having all 16 voices through a single audio output would be limiting. I still think an FPGA version based on the official quad Pokey spec is the way to go. And let's face it, you would need a carrier board to mate it to the standard 40 pin DIP socket anyway. So that same carrier can have the necessary decoding circuits added to allow it to be dropped into an A8. Also I would suggest the carrier board routes one audio output to the original audio output pin, as well as to a header which is also shared by the 3 other audio outputs. These can then be mixed with a simple buffer circuit however you wish (i.e., 8 voices to left and 8 to right, or keep them as 4 voice individuals for surround). the decoding should put the first Pokey at the normal $D2xx address, with A4 toggling between the 1st and 2nd Pokey same as a standard stereo board. The 3rd and 4th Pokey's can be enabled by A5, with A4 individually selecting either Pokey3 or Pokey4.

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Was googling for the pinout and noticed that a quad pokey fpga board exists: https://hotrodarcade.com/products/new-atari-quad-pokey-eliminator-replacement-board

 

The price is reasonable considering that 4 Pokey chips would set you back $80, and the cost of a board, sockets, and some glue logic would be at least another $10-15, bringing the total close to $100 and you would still be looking at assembly. But I wonder if there is at least one complete Pokey core with keyboard scan, paddles, and SIO?

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Was googling for the pinout and noticed that a quad pokey fpga board exists: https://hotrodarcade.com/products/new-atari-quad-pokey-eliminator-replacement-board

I designed that board. As of now it is really meant only for Atari's "Major Havoc" arcade game -- a pretty small market! For reasons I don't yet understand, QPokey doesn't work with the other arcade titles that use the Quad POKEY (I, Robot and Return of the Jedi, and Firefox). While in theory you might be able to generate sound by sending the QPokey commands from an Atari A4 or A8 using the POKEY data and address lines (and some way to work the QPokey's R/W line and four chip selects), I wouldn't guarantee success.

 

I've continued to work on this project and am trying to develop an FPGA POKEY that works in Atari home computers. What I've discovered is that it's much easier to get an FPGA POKEY to work with the Atari arcade games since they seem to use only certain features of a real POKEY -- namely, the data I/O and sound generation -- and ignore the others (e.g. IRQ's, analog potentiometer reads, and serial I/O).

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I designed that board. As of now it is really meant only for Atari's "Major Havoc" arcade game -- a pretty small market! For reasons I don't yet understand, QPokey doesn't work with the other arcade titles that use the Quad POKEY (I, Robot and Return of the Jedi, and Firefox). While in theory you might be able to generate sound by sending the QPokey commands from an Atari A4 or A8 using the POKEY data and address lines (and some way to work the QPokey's R/W line and four chip selects), I wouldn't guarantee success.

 

I've continued to work on this project and am trying to develop an FPGA POKEY that works in Atari home computers. What I've discovered is that it's much easier to get an FPGA POKEY to work with the Atari arcade games since they seem to use only certain features of a real POKEY -- namely, the data I/O and sound generation -- and ignore the others (e.g. IRQ's, analog potentiometer reads, and serial I/O).

 

Very nice looking board :thumbsup: . So what is the decoding scheme for addressing each Pokey? Do you have a schematic showing the pin outs?

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Very nice looking board :thumbsup: . So what is the decoding scheme for addressing each Pokey? Do you have a schematic showing the pin outs?

Thank you for the compliment. The follow-on product I'm working on will be the same size as the original POKEY and will look even cooler, with teensy parts and itty bitty traces. :)

 

The pinout of QPokey is the same as for a real Quad POKEY: https://imgur.com/a/uFE3m

 

The decoding scheme could not be simpler. Each POKEY has its own chip select (!CS1 to !CS4), so to write to POKEY n, you simply load the address and data onto the busses, set R/W, and strobe !CSn low.

 

The interesting thing about QPokey is that it has room in the FPGA for lots and lots of POKEY cores, and lots of external pins to address those cores. Fancy a 64-core POKEY? (A quad-quad-quad POKEY?) I could rewrite the QPokey code to implement that in about 10 minutes. (Though the FPGA in the existing boards is only large enough to hold, I think, eight cores, there are other devices in the same family with *much* more storage.) As it is, the address decoding uses four pins for four cores, but in a custom application those four pins could be used as an address to point to one of 16 cores. And of course the FPGA has lots more pins that could be dedicated to address decoding.

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I hope you don't mind me embedding the schematic image so that it's easier to talk about.

 

RJ7cFpa.png

 

So I'm curious what P0-P7 are being used for? I realize its a dipswitch input, but to configure what?

 

And why the 3 audio channels into one, with only one channel standing on it's own?

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I hope you don't mind me embedding the schematic image so that it's easier to talk about.

So I'm curious what P0-P7 are being used for? I realize its a dipswitch input, but to configure what?

 

Arcade games typically use DIP switches to allow operators to change settings such as game difficulty, number of lives, bonus settings, coin settings, and more. Which game was this diagram from? Major Havoc, Star Wars? With that, I can give you the specific answers.

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So I'm curious what P0-P7 are being used for? I realize its a dipswitch input, but to configure what?

 

And why the 3 audio channels into one, with only one channel standing on it's own?

The schematic I linked to is from Major Havoc. As jmmcorm mentioned, P0-P7, in most Atari arcade games, are connected to DIP switches for setting game and pricing options. The only game I know of in which they're not connected to DIP switches is Warlords, which has the POKEY pot inputs connected to the four rotary controllers.

 

Beats me why channels 1-3 are mixed together by one op-amp while channel 4 gets its own op-amp. I've wondered about that myself. Seems pointless especially when, further downstream, the outputs of those two op-amps are mixed to a single channel so that the game board has only a single audio output.

 

 

Edited by shupac
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The schematic I linked to is from Major Havoc. As jmcorm mentioned, P0-P7, in most Atari arcade games, are connected to DIP switches for setting game and pricing options. The only game I know of in which they're not connected to DIP switches is Warlords, which has the POKEY pot inputs connected to the four rotary controllers.

 

Here are your DIP settings:

http://gamearchive.askey.org/Video_Games/Manufacturers/Atari/dips/havoc_dip.txt

 

Regarding the audio...

You're right, on the surface, it doesn't make sense. Everything you said, and that the cabinet used the standard Atari Audio Regulator II board, which was mono (in that period, when they wanted Stereo like in a Star Wars cockpit, they used two AR-II boards). I'm wondering if it was a last minute cost reduction, or if they had to partially isolate one of the channels to maintain audio quality? I don't know.

 

EDIT: I looked at the schematics. Wow. Okay. This is different than Atari's standard audio configuration. They end up using the SPKR1 and SPKR2 outputs of the AR-II board, but they do NOT use the SPR1-RETURN and SPKR2-RETURN. Instead, they wire one speaker in parallel to SPKR1 and SPKR2, and then they wire two speakers in series and connect them to SPKR1 and SPKR2. So I'm going back in my mind and recalling what the PCB sounded like when I installed it in a Tempest cabinet. The sounds were very un-POKEY like in how they were 'wavy'. I'm wondering if that final audio channel is used [lacking the correct audiophile term] to "modulate" the final output from the other three channels (which might ordinarily make standard POKEY tones) in order to give it a much cooler effect?

 

NOTE: If I'm understanding this correctly (and I could very well be wrong -- I'm out of my depth here), it might suggest a cool additional feature, not actually part of the Major Havoc quad pokey but could be built onto a quad POKEY for 8-bit machines: a register which allows the audio channel from the 4th POKEY to replace/modify ground on the other channels?

 

FOR COMPARISON: The schematics for Star Wars [PDF] (look at PDF pages 114 and 115). It is another Quad Pokey machine, and the schematics will show four speakers just for the cockpit option. I read somewhere that this wasn't an actual stereo machine but the POKEYs and speech output were summed together into a single mono channel and then stereo was produced by introducing a slight delay in the audio on the second channel? (PDF pages 143 and 144 seem to demonstrate how this was done.) Regardless, I was just wanting to show the audio wiring into the AR-II board, and the connections going out to the speakers which use the SPKRx and SPKRx-RETURN lines in the expected and conventional manner.

Edited by jmccorm
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