Next:
- Try 68000 only, without the PAK at all

Okay, next test:
- Assemble a 68000 on top of the PAK
- Remove J5 (disable the PAK, enable the 68000)
Switch on.

Forgottenmyname wrote: ↑

Mon Jan 28, 2019 6:33 pm

Ok, so I should acquire some of the SRam but until then disable the SLC?

The speed gain it's definitely worth!
Or the other way round: Sell your Tag-RAMs as well! I noticed there are people desperately looking for it..

Please change to the following jumper settings:
J9: 1-2 (set CPUCLK to 32MHz)
J10: 1-2 (set FPUCLK to 32MHz)
J4: on (disable the second level cache)
Keep everything else as is.. and switch on!

SRAMs are needed for the Second Level Cache, since this is where the cached data is actually stored.
Basically you can run the PAK without SRAMs, but only with the cache disabled.. and thus with lower speed..

And yes, IDT71B74S20Y or MK48S80 are both fine as well. 25ns is enough for 32MHz.

Furthermore it seems there are no SRAMs assembled underneath the TOS ROMs..

Ok, got it.
Your PAK PCB is not the official release, but a later copy with a design flaw. We will fix it..

No further try and error.. we will start from scratch!
Let us go for the PAK030 first. I am waiting for your jumper settings and your photos of the PAK.

When installed, was the the 68000 mounted on top of the PAK?
And did everything work properly with the 68000 enabled, and the PAK being disabled?