Memory IC's for PCML Q+?

[t0nyt]

Fitted Memory and on first boot Minerva still reported 128KB total memory, so does seem to be a 0KB version

On subsequent boots the QL wouldn't start with the card installed so will have to strip out memory chips and re-test without them to see if it still works

Does anyone know if the 0KB card should work in conjunction with other memory expansions or whether it only works with a 128KB QL please?

Many thanks

[t0nyt]

Solved the problem with the card (helps if you plug it into the QL completely...) but memory not recognised

I guess I join the list of people looking for a 256kb PAL!

Still intrigued as to whether the card should work with other memory expansions though? please

Many thanks

[t0nyt]

Could anyone give me any idea what I need to read a PAL and duplicate it using an equivalent GAL please?

EDIT: or just to read and write to new PAL's

(I only have a GQ-4X V4 and I’m pretty sure that can’t do it)

Many thanks

[t0nyt]

Also, is the IC marked "DMPAL16R4ANC" the "PAL" in question please? EDIT: Yes it is

The 16Kb ROM on the board is an MBM27128-25, but I assume this is just a normal EPROM? EDIT: Yes it is

I do now have a PCML Q+ with working 256kb RAM on-board, but would like to try and get my original 0kb board working

Many thanks

[t0nyt]

Just read both EPROM's and they are identical so there's no code in there specific to 0k vs 256k at least

[t0nyt]

From what I can see programmers for something like this are £1k+

Am going to call it quits and strip out the memory chips I added to the 0kb board and just keep them as separate 0k and 256k versions

(Maybe I’ll come across a broken board in the future I can get a suitable PAL from)

[Derek_Stewart]

Hi

I have a PCML board that only the Floppy Disk controller works.

I had assumed the PAL responsible for the Memory expansion mapping was faulty, I thought there was a fix for this, but I will have to look at my old records.

[t0nyt]

Hi

I have a PCML board that only the Floppy Disk controller works.

I had assumed the PAL responsible for the Memory expansion mapping was faulty, I thought there was a fix for this, but I will have to look at my old records.

From what I've read elsewhere on here there are different PAL's for 0k & 256k (and in a document on dilwyn's site about different interfaces I think)

If there is another way that would be great please

Thanks

[t0nyt]

Was looking at the DuPal GitHub (for brute force reading the PAL) but I wouldn’t know how to even go about getting a PCB made

[t0nyt]

I just realised that the Q+ is emulated in MAME (uses identical v1.14 ROM too)

Not knowing anything about MAME, I had hoped someone had emulated (read) the PAL data but there's no sign of a file for that as far as I can see

But surely to emulate the Q+ (unless it really only emulates the 0k version) they'd have to also emulate the PAL in some way?

EDIT: seems MAME doesn’t emulate PALs

Sorry for the ramblings