Mac Plus ROM issue

[takane2]

Hello all. I have a mac plus with a unidentified upgrade board(68030,FPU and RAM) that I recent got from someone who was moving. When I turn it on it gets the sad mac error for ROM checksum.

I pulled the rom chips and was able to dump them okay but I want to compare them to a known good dump and if they have been corrupted somehow, replace them with 27C512s. The problem is I havn't been able to find rom dumps that match the ROM revision I have. I have 342-0342-A and 342-0341-B. EVerything I can find is for the b and c revisions respectivly. I did fine files that are allegedly the same chips as mine here: http://apple2.org.za/gswv/a2zine/GS.WorldView/v2000/Aug/MiscNew/MiscA2ROMs/ROMS%20Folder/ but both files differ after 0x0100 which is suspect. I think they are a different version rather than a indication that mine are corrupted.

Does anyone have a plus with the same version ROM as me? Would you be willing to dump the chips so I can compare them to my dump?

Thanks!

 

[360alaska]

Does this help?

https://archive.org/details/mac_rom_archive_-_as_of_8-19-2011

They list v1,2 and 3 for mac plus. You'll need to split the file to high/low images, I know theres a program to do that somewhere on the forum...

good luck...

 

[takane2]

Thanks, I was just googling the part numbers so I didn't find that.

The checksum bits from my dump matched the v2 ROM, but other than the very begining nothing else matched. So the rom must have been corrupted somehow. I'm going to get some 27C512s and replace them. Can I burn v3 or is the logicboard different for v3 Plus ROMs?

I couldn't find the software you mentioned(I didn't look long) and I was bored so I wrote two simple perl scripts to interlace and deinterlace two files. I attached it incase anyone was interested.

romutil.zip

 

[lameboyadvance]

This page describes the different versions of the Mac Plus ROM. Most revisions were to fix SCSI issues.

AFAIK all ROM version will work in all Pluses. It is probably best to have the latest version, though I don't know if any of the fixed issues affect newer devices like the SCSI2SD or the Floppy Emu.