(Regular) Pokey in FPGA?

[+Larry]

I was curious if anything like this has been done for Pokey replacements.  I saw an advertisement for the BackSID  for $32.00, so it seems logical that a Pokey replacement could be done for a similar price (say under $50).  But no bells and whistles -- just a good Pokey replacement.

 

https://store.backbit.io/product/backsid/

[Synthpopalooza]

Yes.  It's called HOKEY.

[reifsnyderb]

Where is this "HOKEY" found?

[Ricky Spanish]

3 minutes ago, reifsnyderb said:

Where is this "HOKEY" found?

it's for the Atari 7800 .

[+scorpio_ny]

The Hokey is a sound only implementation of the Pokey chip used for certain cartridge games on the 7800.

Here is more info: https://forums.atariage.com/topic/321741-hokey-demo/page/2/#comment-4968839

 

Edited March 11 by scorpio_ny

[Rybags]

How about PokeyMax?

 

https://atari8.co.uk/firmware/pokeymax/

 

Although you could call it a bit of overkill - stereo, SID and Covox also included.  But, if there's space to spare then why not?

[+Larry]

7 hours ago, Rybags said:

How about PokeyMax?

 

https://atari8.co.uk/firmware/pokeymax/

 

Although you could call it a bit of overkill - stereo, SID and Covox also included.  But, if there's space to spare then why not?

I'm focusing on the price for an original type replacement.  BackSID at $32.  Pokeymax 3 is going to be apx. 150 Euros + shipping.  IIRC, TBA was selling used Pokeys for $65.  On eBay, $60-$80 used.  There is a Pokey One apparently for arcade machines for $50 and a Version 2 for $75, but at least the original version says "not for computers."  Don't know about the V2 for computer use.

[_The Doctor__]

v1 not for SIO prolly

[chevymad]

Version 1's work for the 2nd pokey in a stereo setup. Though they're a bit taller. I haven't tried a version 2 in the primary pokey spot yet to see if the non audio parts work. 

[+mytek]

6 hours ago, Larry said:

I'm focusing on the price for an original type replacement.  BackSID at $32.  Pokeymax 3 is going to be apx. 150 Euros + shipping.  IIRC, TBA was selling used Pokeys for $65.  On eBay, $60-$80 used.  There is a Pokey One apparently for arcade machines for $50 and a Version 2 for $75, but at least the original version says "not for computers."  Don't know about the V2 for computer use.

$75 for a full "stock" Pokey replacement seems a bit steep to me, since I'm fairly certain Brad still has them for sale a lot cheaper, albeit only one per order (yep last update July 23 shows it as $30 and in stock). So what would compel me to spend an extra $45 ?

 

What is making the cost of an FPGA version so expensive?

[reifsnyderb]

2 minutes ago, mytek said:

What is making the cost of an FPGA version so expensive?

My question x 100.

 

 

 

 

 

 

[pcrow]

Having watched a number of repair videos, I'm under the impression that the various replacements for Pokey sometimes have subtle timing issues.  Those usually only show up with the right combination of other modifications and sometimes PAL or NTSC timings.  Something to investigate, especially if you might want to be adding in a bunch of other mods.  If someone knows more about the details, I'm curious.  I'm also not clear on whether the existing Pokey FPGA cores are recreated from the chip specs or copied from high-res photos of an exposed chip (I know the 6502 was reverse-engineered that way to get it transistor-perfect).  And is the FPGA code or chip design for Pokey available publicly, or are people selling products based on them keeping them private (which would help explain prices)?

[+mytek]

1 minute ago, reifsnyderb said:

My question x 100.

Too funny... I got a giggle reading your response

 

Even $50 for the hobbled Pokey One (audio only) is ridiculous since the Best Electronics supplied full featured "real" Pokey is still $20 less. The only thing that I see would or should make someone want to go the more expensive route is if they have an immediate need for more than one chip. Especially from an audio purist perspective, you're probably going to want a "real" Pokey instead of an FPGA version anyway.

[+MrFish]

You can get real POKEYs on Ebay regularly for $30 or less too, by just buying a copy of 7800 Ballblazer.

 

[manterola]

54 minutes ago, mytek said:

I'm fairly certain Brad still has them for sale a lot cheaper, albeit only one per order

I would like to have at least one Atari 8bit with the stereo implementation, but I already got one POKEY from Brad. It is only ONE per person (for life). I got mine like 5 years ago, and he did not want to sell me another one.

I also need to fix a 600XL half failing POKEY (keep repeating key presses, but probably good for stereo). Anyway, what I am trying to say is that there are valid reasons to get more than one POKEY.

26 minutes ago, MrFish said:

You can get real POKEYs on Ebay regularly for $30 or less too, by just buying a copy of 7800 Ballblazer.

 

I have been waiting for a Ballblazer cartridge for 1.5 years. I have notification in all the typical online sites and apps, still nothing reasonable (I guess Saturday, there were a guy selling the cartridge at $35 plus $7.99 shipping, which is the first time I encounter that, and it actually matches the price range you mentioned). I also got a bit concerned of destroying a cool and a bit hard to find cartridge to use the POKEY inside.

 

So now I am just seriously considering using one of my computer to supply spare parts (cannibalize it), for example using an 800XL or 600XL for the Delay line, the Pokey, the keyboard MB connector, the plastic piece over the cartridge, etc.

 

In summary, I really think there is a market for the perfect implementation of POKEY without extras using the cheapest FPGA possible.

 

Edited March 11 by manterola

[+MrFish]

13 minutes ago, manterola said:

I have been waiting for a Ballblazer cartridge for 1.5 years. I have notification in all the typical online sites and apps, still nothing reasonable (I guess Saturday, there were a guy selling the cartridge at $35 plus $7.99 shipping, which is the first time I encounter that, and it actually matches the price range you mentioned).

I just searched 5 minutes ago. I found several that had sold in the last few months for $15 - $25, + $5 shipping, and a bunch more that sold recently for $30 - $35, some + $5 shipping, some with free shipping. I saw active auctions of one being bid on still, currently at $11.50 + $5 shipping, and one with a ripped label (who cares?) with a starting bid of $30 and $5 shipping, with no bids yet... and then it continues on with more for $38 + $5 shipping, etc. I can't see how it'd take very long to get one for the price range I mentioned if you were really looking regularly.

 

20 minutes ago, manterola said:

I also got a bit concerned of destroying a cool and a bit hard to find cartridge to use the POKEY inside.

Yeah, I was posting this (in part) to stir up some ethics.

 

[+-^CrossBow^-]

Not to stir up too much trouble here...

 

But first Brad will only sell you one Pokey for life! He keeps a list and both the Pokey and TIA chips are basically one purchase, per person for life. As a result, from a service standpoint, Bradley can't be used unless the owners of the systems being repaired purchase the Pokey and send it to the tech doing the work. And if that person has more than one Atari 8-bit or requires repairs involving pokey's for multiple systems... then you are out of luck and they have to come from somewhere else.

 

Regarding 7800 BallBlazer carts. I've pulled 2 pokey chips from BB carts that worked and sounded fine when playing them. However, when pulled and installed into a 5200, I found out one of them didn't have working controller pot reads. And had other errors coming up. So it was basically only usable for the audio. The other one faired better, but when I used it with my stereo pokey setup, the audio from that chip was badly distorted. I put it back into a BB cart and it sounds fine. I ended up using a different pokey from a donor 5200 mainboard in my stereo pokey setup and that worked great.

 

So I'm of the opinion that some of the pokeys stuck into BB and Commando carts could be defects repurposed for the games since the defects didn't affect what the pokeys were needed for in those games. And that wouldn't really surprise me if Atari kept them and found a nice use for them that otherwise wouldn't have been useful.

 

[_The Doctor__]

You use the real pokey from the cartridge and install a hokey or pokey 1 in the cartridge.

Now you have a working cartridge and a working Atari 8 bit.

[reifsnyderb]

I don't think the work-arounds really matter.  The issue I see is that Atari has three LSI chips for which there is no one-for-one replacement for.  An FPGA could probably be used for the Sally chip, too.  The theory is that the FPGA is supposed to be the magical wonder chip that can do anything.  The reality is otherwise.

[Jfcatari]

3 hours ago, MrFish said:

You can get real POKEYs on Ebay regularly for $30 or less too, by just buying a copy of 7800 Ballblazer.

 

This is where I get pokies from. Just grab that desoldering iron and she is free.

[chevymad]

I was going to say it's a lifetime limit of one from Brad. Which I used years ago. I can never find a ballblazer cart for reasonable when I want one either. I think I now own 2 PokeyOne's because of that. One's a version 2, but I haven't tried it in the primary position.  I also found out the hard way that an 800xl mechanical keyboard will short on a pokey one in a tkII stereo board, but not an original pokey. So my pokeyones are now in both of my 1088s. 

[_The Doctor__]

I still think resistors should be used with the mechanical keyboards XE style for the console keys. might be helpful. Make sure to let pokey one makers know what happens, and soften the blow on real pokeys.

[+selgus]

14 hours ago, -^CrossBow^- said:

Not to stir up too much trouble here...

...

So I'm of the opinion that some of the pokeys stuck into BB and Commando carts could be defects repurposed for the games since the defects didn't affect what the pokeys were needed for in those games. And that wouldn't really surprise me if Atari kept them and found a nice use for them that otherwise wouldn't have been useful.

 

I did not know this.. thanks for this info!

[+scorpio_ny]

16 hours ago, reifsnyderb said:

I don't think the work-arounds really matter.  The issue I see is that Atari has three LSI chips for which there is no one-for-one replacement for.  An FPGA could probably be used for the Sally chip, too.  The theory is that the FPGA is supposed to be the magical wonder chip that can do anything.  The reality is otherwise.

Actually, there are two active replacements that work.(GTIA—> Sophia2, Pokey—>Pokeymax). The issue is that they are not low cost replacements.

 

On 3/10/2024 at 5:39 PM, Larry said:

I was curious if anything like this has been done for Pokey replacements.  I saw an advertisement for the BackSID  for $32.00, so it seems logical that a Pokey replacement could be done for a similar price (say under $50).  But no bells and whistles -- just a good Pokey replacement

I believe the reason why it is cheaper is because it is not based on a FPGA but actually an ARM cortex based chip. Thus the lower cost. Another popular SID replacement, ARMsid, is definitely based on an ARM cortex chip.

[reifsnyderb]

18 minutes ago, scorpio_ny said:

Actually, there are two active replacements that work.(GTIA—> Sophia2, Pokey—>Pokeymax). The issue is that they are not low cost replacements.

 

They are not one-for-one replacements, either.