A new generation of PLA for the C64 is now available.

Disk drives, Monitors, SuperCPU etc.
Stealth
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Re: A new generation of PLA for the C64 is now available.

Post by Stealth » Mon Apr 03, 2017 9:10 am

Ordered two for myself - can't wait to finally see the breadbox boot up!



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Re: A new generation of PLA for the C64 is now available.

Post by eslapion » Sat May 06, 2017 1:01 am

Just a word of warning concerning a PLA sub selling on eBay that also uses the XC9536XL: Me and Fredric have examined this product and we were curious as to why it would carry the 5ns version of that chip - PLAnkton carries the 10ns version.

Considering the speed of a C64 and that most other PLA substitutes have problems because they are actually too fast, there is absolutely no logical reason to use a faster chip that also turns out to be considerably more expensive - PLAnkton uses the 10ns version of the XC9536XL, it is the slowest and cheapest member of that family of chips and only it has the necessary characteristics to faithfully replicate the slow N82S100 on which the Commodore PLA was based.

Upon closer inspection, we have determined that the reason why the 5ns version was chosen is because it is in fact Chinese made counterfeits. Chinese clones of the XC9536XL are all marked as 5ns but they have all sorts of different response speeds. Also, on these counterfeit ICs the slew rate limiter as well as the low power mode don't operate properly. Of course, they are considerably cheaper than all genuine Xilinx XC9536XL, no matter what their rated speed may be.

PLAnkton uses only genuine Xilinx XC9536XL circuits purchased from Digikey, an authorized distributor of Xilinx products. We program these chips to provide the most accurate reproduction of the behavior of a genuine C64 PLA as well as the lowest possible power consumption and only a genuine Xilinx circuit can achieve this level of accuracy.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: A new generation of PLA for the C64 is now available.

Post by Gonzo » Mon May 15, 2017 9:19 am

eslapion wrote:
Sat May 06, 2017 1:01 am
Just a word of warning concerning a PLA sub selling on eBay that also uses the XC9536XL: Me and Fredric have examined this product and we were curious as to why it would carry the 5ns version of that chip - PLAnkton carries the 10ns version.

Considering the speed of a C64 and that most other PLA substitutes have problems because they are actually too fast, there is absolutely no logical reason to use a faster chip that also turns out to be considerably more expensive - PLAnkton uses the 10ns version of the XC9536XL, it is the slowest and cheapest member of that family of chips and only it has the necessary characteristics to faithfully replicate the slow N82S100 on which the Commodore PLA was based.

Upon closer inspection, we have determined that the reason why the 5ns version was chosen is because it is in fact Chinese made counterfeits. Chinese clones of the XC9536XL are all marked as 5ns but they have all sorts of different response speeds. Also, on these counterfeit ICs the slew rate limiter as well as the low power mode don't operate properly. Of course, they are considerably cheaper than all genuine Xilinx XC9536XL, no matter what their rated speed may be.
According to Fredric that's just rumor. Sorry I can't link the source but here is the quote:
e5frog wrote: J-PLA is a new one, has anyone made any tests on it (not just tried running a game but actually checking the ramp time etc).
It's rumored it uses Chinese knock-off CPLD, haven't actually asked Jani about it (the guy who makes them).

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Re: A new generation of PLA for the C64 is now available.

Post by e5frog » Mon May 15, 2017 9:23 am

In the next reply Jani himself (maker of J-PLA) confirmed that he has used counterfeit chips.
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Re: A new generation of PLA for the C64 is now available.

Post by Gonzo » Mon May 15, 2017 10:09 am

Sorry, I somehow missed that. For the record and to avoid any misunderstanding:
Posted: Fri May 12, 2017 10:43 am
Janilaa wrote:
e5frog wrote:J-PLA is a new one, has anyone made any tests on it (not just tried running a game but actually checking the ramp time etc).
It's rumored it uses Chinese knock-off CPLD, haven't actually asked Jani about it (the guy who makes them).
Few of the first had chinese-sourced CPLD, but then I ordered a lot from Digikey, which I assume to be selling only genuine. So, all the latest I've been selling and every J-PLA in the future uses a genuine chip. Don't want to take risk of CPLD's failing.

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Re: A new generation of PLA for the C64 is now available.

Post by eslapion » Mon May 15, 2017 9:24 pm

Gonzo wrote:
Mon May 15, 2017 9:19 am
According to Fredric that's just rumor. Sorry I can't link the source but here is the quote:
The rumor came BEFORE the actual checking and confirmation.

I confirm to you that we were sold a unit which carried a counterfeit XC9536XL.

This being said, J-PLA is priced at 18.50$US while PLAnkton is priced at 17.25$US.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: A new generation of PLA for the C64 is now available.

Post by e5frog » Mon May 15, 2017 10:58 pm

I don't mind if people buy all the other PLA replacements, then they can buy ours if (when) they get problems. That said you can of course use a non fully functional PLA for years and not have any problems - until you try that special cart or fun new hardware and it starts to crash now and then. ;-)

On a side note, we have discussed making colored PCB:s - any particular color that's preferred over plain green?
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Re: A new generation of PLA for the C64 is now available.

Post by Stealth » Wed May 17, 2017 2:24 pm

A black one so it would fit the overall theme of the C64 Reloaded? (assuming the new revision due out soon is black as well)

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Re: A new generation of PLA for the C64 is now available.

Post by eslapion » Thu May 18, 2017 1:32 am

Stealth wrote:
Wed May 17, 2017 2:24 pm
A black one so it would fit the overall theme of the C64 Reloaded? (assuming the new revision due out soon is black as well)
Do you like black and gold ?
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders

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Re: A new generation of PLA for the C64 is now available.

Post by Stealth » Thu May 18, 2017 10:00 am

Black and gold would be very elegant - alas, I cannot guarantee I'd get one, seeing as I just had two delivered from e5frog not two weeks ago!

Also, the breadbox it was supposed to go into started working all of a sudden. Very unusual. At least I have spares if something goes astray.

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