K2000 Calvin Rev A Engine Board Upgrade

Greetings
I recently acquired a K2000 from charity shop.
It is in excellent condition but is running Version 1 software. I would like to upgrade the OS to 3.87 but have run in to an issue.
The unit has a Revision A Calvin Engine board which does not have JP7.
I tried 3.87 Engine EPROMs which booted OK , but I am unable to get the Setup EPROMs version 5 or 6 to work.

I have been searching the internet for details but have found only a reference to some sort of physical modification required for Rev A Calvin boards, does anyone have the details of this mod?

Regards Tony

I know there is a different version v3.87 for the Janis and the Calvin versions. Are you sure you have the right one? If you see a J after it when you first boot then that’s a clue.

I recently recapped and updated my K2000RS to the K2VX version with the updated setup ROMs and the Contemporary and Orchestral ROMs, worth the effort!

I’ll have a look around for some of the documentation I got with the parts, I know that JP7 isn’t on the Calvin version board (you can solder a jumper) but if I recall correctly that’s just for the expansion ROM cards.

Hi tony, i think i had the same problem, just solder in jp7, either with a plug or a jumper wire or whatever really, the silkscreen should be there just not the jumper itself if it’s the same as mine, so just jump the 2 contacts in a semi-permanent fashion (i used like a half inch of solid conductor wire folded), don’t make it too long either if you expect to install the P/RAM upgrade later

Hi Dataslider

Unfortunately the Rev A Calvin Engine board in my K2000 appears to be one of the first produced and there is no sign of JP7. It is like they thought they would never need EPROMS bigger than 2M in the future.

I have looked at the schematics and I understand what is required, pin 31 of the EPROMS needs to be connected to CA19 rather than +5V, just not sure how to put this in to practice.

I will either have to find time to dismantle the K2000 to examine the Engine board or leave it as is with OS v1.0 rather than v3.87.

recommend both disassembly and upgrade if at all possible, maybe you’ll notice something looking at the board itself, i’ll check what rev my board is next time i have it open which should be within the month

https://images.reverb.com/image/upload/s--fhymy2uT--/f_auto,t_supersize/v1558307041/uyirdxtwegmfmma4y9wd.jpg guess it looks like this one? with only one jumper instead of 2?

Yes that looks like my engine board, Rev B instead of A but missing the second jumper JP7.
I will set some time aside to dismantle my unit and see what is on the underside of the PCB.