128K ROM sets for 128Ke, 512K, 512Ke and Plus

[lumpydog]

What is the difference between the 3 128K ROM sets ?

Pina writes that there were three versions.

You can determine the version by pushing the interrupt button and typing "DM400000" without the quotes at the ">" prompt

Top row - top of the second and third columns - the version numbers work out as follows:

4D1E EExx = version 1

4D1E EAxx = version 2

4D1F 81xx = version 3

So what's the difference between these 3?

Does anyone know the difference? The reason I ask - I have version 2 ROMS in my Mac and I have a set of version 3 ROMS handy - I'm wondering what the difference will be if I put them in a 512K Mac....

Lumpy

 

[Charlieman]

Almost nothing:

http://developer.apple.com/technotes/hw/hw_11.html

 

[lumpydog]

Thanks!

 

[Mac128]

Almost nothing:http://developer.apple.com/technotes/hw/hw_11.html

If that tech note wasn't absolutely clear, the 512Ke shipped with the 1st revision ROM and did not require the 2nd revision ROM unless you bought a Dove, or other, add-on SCSI board. Since the ROMs relate mainly to SCSI, you'll want to use the 1st revision in your stock 512Ks and reserve the "good" ROMs for your Plus. The 1st revision ROM could send your Mac into an endless startup loop with certain SCSI drives, though unlike the original ROM you could still boot from a floppy drive.