The elusive KU boards.

Disk drives, Monitors, SuperCPU etc.
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eslapion
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The elusive KU boards.

Post by eslapion »

A few years ago, Thomas 'Skoe' Giesel tested a bunch of different original PLAs as well as a few PLA substitutes. This include my earlier generation of PLA substitutes based on genhine ST M27C512-90B6 which I call PLAkate.

Skoe confirmed my claims genuine ST PROMs don't cause bus contentions as well as consume considerably less power than original PLAs but he also indicated both PLAkate and the SuperPLA have problems with boards with KU serial numbers.

I have designed the electrical architecture of PLAnkton to replicate the timing specifications of earlier generations of PLA and as such, they are slower than both PLAkate and the SuperPLA. Did anyone use PLAnkton with these boards.

Also, could anyone tell me what the exact assy number of these KU boards is? I have never owned or even seen any of these boards.

Thank you all.


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Re: The elusive KU boards.

Post by eslapion »

For some information here but this is very sketchy.

https://www.c64-wiki.com/index.php/Moth ... KU-14194HB

Anyone with more information about this series of boards?
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Re: The elusive KU boards.

Post by motrucker »

eslapion wrote:A few years ago, Thomas 'Skoe' Giesel tested a bunch of different original PLAs as well as a few PLA substitutes. This include my earlier generation of PLA substitutes based on genhine ST M27C512-90B6 which I call PLAkate.
Skoe confirmed my claims genuine ST PROMs don't cause bus contentions as well as consume considerably less power than original PLAs but he also indicated both PLAkate and the SuperPLA have problems with boards with KU serial numbers.
Thank you all.
Skoe just posted on REMOVED, and left this: http://skoe.de/easyflash/doku.php
I don't see any direct references, but maybe you can contact him?
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eslapion
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Re: The elusive KU boards.

Post by eslapion »

@motrucker
Tried contacting him on Denial and e-mail... got no reply.

I'm just so glad he kicked the butt of Jens with his 2.5v threshold levels stories and CMOS parts imaginary problems.
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Re: The elusive KU boards.

Post by banman »

Hi eslapion,

eslapion wrote: Mon Oct 26, 2015 2:36 pm A few years ago, Thomas 'Skoe' Giesel tested a bunch of different original PLAs as well as a few PLA substitutes. This include my earlier generation of PLA substitutes based on genhine ST M27C512-90B6 which I call PLAkate.

Skoe confirmed my claims genuine ST PROMs don't cause bus contentions as well as consume considerably less power than original PLAs but he also indicated both PLAkate and the SuperPLA have problems with boards with KU serial numbers.
I have 2 KU style C64 mainboards. I can confirm that the above statement as far as I can tell with my shoddy testing.

It is interesting to note that both the KU style boards have different components added ad-hoc at the factory to one another.

I have used an original genuine ST M27C512-90B6 PLA EPROM based substitute on both KU style boards and have not detected any glitches with an oscilloscope on !ROML or !ROMH pins of the PLA as yet.
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Re: The elusive KU boards.

Post by eslapion »

That's interesting. I assume you procured a genuine ST PROM from Ray Carlsen. This RPOM, when used as a PLA sub has a CASRAM latency that's about 10ns too short so it should work correctly only on boards 250425, 250466 and later revisions of the 250407 which have the R42/C204 RC filter.

Of course, it is always possible to manually add the components to the KU boards.
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Re: The elusive KU boards.

Post by banman »

Hi eslapion,
banman wrote: Fri Aug 07, 2020 4:46 am I have used an original genuine ST M27C512-90B6 PLA EPROM based substitute on both KU style boards and have not detected any glitches with an oscilloscope on !ROML or !ROMH pins of the PLA as yet.
Apologies, I have misquoted the ST M27C512-90B6 PLA EPROM. I in fact have these pair of original Genuine ST 27C512-90F1 EPROMs. :oops:

20120416-122438.jpg
DSCF4055 Genuine ST 27C512-90F1 cropped.jpg
DSCF4055 Genuine ST 27C512-90F1 cropped.jpg (14.13 KiB) Viewed 3936 times
I had seen a separate post from you regarding the use of E/PROMS as C64 PLA substitutes.

I was actually doing something totally unrelated with knockoff (fake) E/PROMS and found some (but not all) worked as a suitable E/PROM based C64 PLA substitues. I was curious and wanted to pursue this further.

Late last year an electronics shop near me was closing down. I was fortunate enough to come across a pair of these chips amongst other things. After close inspection the owner and I were confident that these were original and not fake (knockoff EPROMS).

I saw this old thread and remembered that I'd tested them in 2 KU style mainboards. I actually thought I'd lost them in amongst all the other stuff I had got from the electronics shop and I dug them out just now.
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