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+2A ROMs 0 - 3 on 2x Eprom

Posted: Mon Jun 22, 2020 5:22 pm
by Erm
Just to verify before I burn the ROMs.... the Spectrum +2A/+2B/+3 physically have 2x 32k ROM chips, usually referred to as A and B. I know that they consist of 4 banks of 16k ROM data.

Am I right in thinking that ROM A contains 16k ROMs 0 and 1 (with 0 starting at the beginning and 1 in the 2nd half) and that for ROM B it's the same principle, with the first 16k space taken up by ROM 2 and the last 16k being ROM 3?

Thanks.

Re: +2A ROMs 0 - 3 on 2x Eprom

Posted: Mon Jun 22, 2020 7:40 pm
by Lardo Boffin
Here is the inside of a +2A currently awaiting attention. Looks like two ROMs.

F16CEA5A-7DC3-454A-A655-BF163FEB5E22.jpeg

Re: +2A ROMs 0 - 3 on 2x Eprom

Posted: Mon Jun 22, 2020 10:35 pm
by Lardo Boffin
Up close if required:

D93BEE89-9AEB-415D-86B2-864BB7C42EA8.jpeg

Re: +2A ROMs 0 - 3 on 2x Eprom

Posted: Mon Jun 22, 2020 11:48 pm
by Erm
Yes, thanks Lardo, I know that there are two but they come as 4x 16k, so just wanting to confirm the correct order that they get burnt onto the chips.

Re: +2A ROMs 0 - 3 on 2x Eprom

Posted: Tue Jun 23, 2020 9:14 am
by Lardo Boffin

Re: +2A ROMs 0 - 3 on 2x Eprom

Posted: Tue Jun 23, 2020 12:02 pm
by Erm
Just to make sure, I'm going to compare the ROM code of my original A&B to verify the 0-3 order.