exxos's Atari, Amiga & retro forum

I think it is strongly recommended to use a PUPLA when your setting is exceeding 32 Mhz, but I might be wrong.

I'm sure I had mine running in an STFM at 50MHz. All I do remember is there is a different set of GAL's for 50MHz.

I'm currently running at 40mhz, both CPU and FPU. No PuPla and it's pretty stable.

For some reason I was thinking that the PuPla helped with the Frak board and maybe
video cards like the Panther?

I could easily be wrong though. It's been a while (years, in fact) since I installed mine.

Probably forgot more than I care to admit. :)

@Acsi @Darklord

IIRC, Darklord is the happy owner of the revised PAK68 board, with a clock buffering on the PCB.

You may have the same revision, Acsi.

My board runs just fine at 40 Mhz and the only noticeable glitches are the artefacts on the screen, as this speed seems to be problematic for the VGA board without any buffering.

I will soon get a configurable oscillator to try different frequencies (over 40 Mhz but less than 50 Mhz) and see what the results are.

And BTW, I have the latest GALs from WRS online fitted on my PAK.

At the moment I have only a PAK68/3-020 with a 25Mhz 020 CPU running at 32Mhz. The Mega ST1 is original with 4,7k and 10k Pullups and has only faster Ram Chips (4MB). It worked fine with my STGA Adapter and a ET4000 card ...

frank.lukas wrote: 22 Jan 2022 13:20 At the moment I have only a PAK68/3-020 with a 25Mhz 020 CPU running at 32Mhz. The Mega ST1 is original with 4,7k and 10k Pullups and has only faster Ram Chips (4MB). It worked fine with my STGA Adapter and a ET4000 card ...


mst.jpg

boot_screen.jpg

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I have only issues (graphic glitches) above 32Mhz.

I am now trying different buffers (LS, ALS and F types) and I have just received today the ALS type ones I was waiting for.

I will give them a try tomorrow if time allows.

meanwhile I still have a PAK68/3-030 with 50Mhz. The VOFA Docu says it only works up to a maximum of 32Mhz. And so it is in my setup.

HigashiJun wrote: 06 Feb 2022 06:19 I am now trying different buffers (LS, ALS and F types) ...

74S types are fast

Tried the buffers today and the results are that only ALS and F type buffers work with my bigger VGA board.

The small factor VGA board only works when the PAK68 is not fitted.

Whatever the buffers are, I have glitches on the screen when the clock is above 32 Mhz.

So as Frank wrote, it seems there is no way to have better speeds with the PAK68 when a VOFA or STGA is also fitted.

:x

I have a Panther/2 + PuPla/2 and a 50Mhz Pak030. So I think thats the only way ...

I guess so.

If I only could get my hands on these...