Macintosh IIcx custom ROM

[luRaichu]

Hi,
I'm looking for a IIcx compatible ROM that only has the memory test disabled and is 32-bit clean. The examples I've found include a ROM disk which I don't want or care for. Thanks

 

[frontein1]

My IIcx is down for the count right now. But you can drop a IIsi ROM in the IIcx. This would give you a 32-bit clean ROM.

So really you probably want a IIsi ROM with just the memory test disabled (and vicariously the ROM checksum altered to not fail) right? If so give the attached a run (assuming you have a SIMM and a programmer handy)

 

[Bolle]

This will do: https://68kmla.org/bb/threads/macintosh-se-30-rom-modifications.49789/
IIcx and SE/30 have identical ROMs.

Edit: a scratch that, I missed you were looking for 32-bit "clean" ROMs.

 

[Joopmac]

I know of and use this one http://synack.net/~bbraun/macsrc/iisi+romdrv0.9+nomem+nosum.bin
IIsi 32-bit clean; No ROM disk, and no RAM test
see http://synack.net/~bbraun/macromboot.html

 

[luRaichu]

So really you probably want a IIsi ROM with just the memory test disabled (and vicariously the ROM checksum altered to not fail) right? If so give the attached a run (assuming you have a SIMM and a programmer handy)

Why is it double the size of a IIcx ROM?

 

[croissantking]

Why is it double the size of a IIcx ROM?

The IIcx ROM was older generation, whereas the IIsi was a newer universal ROM, so it was expanded.
Apple doubled the size of the ROM several times between 1986 and 1998, eventually ending up with 4MB ROMs.

 

[joevt]

Apple doubled the size of the ROM several times between 1986 and 1998, eventually ending up with 4MB ROMs.

68K Macs stopped at 2 MiB.

The first 1MiB ROM is probably this one:

067c.15f1    1991-10 - 420DBFF3 - Quadra 700 & 900 & PowerBook 140 & 170

These are the 2MiB ROMs:

067c.30f1    1994-05 - B6909089 - PowerBook 520 520c 540 540c
067c.30f2              B57687A5 - PowerBook 550c
077d.10f3.1  1994-09 - 5BF10FD1 - Quadra 660av & 840av
077d.2bf1.6  1995-08 - 4D27039C - Powerbook 190 & 190cs

Power Macs switched to 4 MiB to add all the PowerPC stuff.
3 MiB for the 68K part (includes PowerPC stuff that runs in MacOS).
1 MiB for the PowerPC part (ExceptionTable/Startup, HWInit, Nanokernel, 68K emulator, and Open Firmware for PCI Macs).

 

[luRaichu]

How do I split the ROM into 4 parts? I made my own ROM SIMM and am programming each chip manually

 

[Phipli]

How do I split the ROM into 4 parts? I made my own ROM SIMM and am programming each chip manually

Either write a little Python program, or the program that comes with TL866 devices has a slice and dice option in the save window I think
If you're struggling, AI will walk you through it

 

[luRaichu]

AI will walk you through it

Thanks for slopping by

I found these commands here

srec_cat rom.bin -binary -split 4 0 -o U4.bin -binary
srec_cat rom.bin -binary -split 4 1 -o U3.bin -binary
srec_cat rom.bin -binary -split 4 2 -o U2.bin -binary
srec_cat rom.bin -binary -split 4 3 -o U1.bin -binary

 

[Phipli]

Thanks for slopping by

I found these commands here

srec_cat rom.bin -binary -split 4 0 -o U4.bin -binary
srec_cat rom.bin -binary -split 4 1 -o U3.bin -binary
srec_cat rom.bin -binary -split 4 2 -o U2.bin -binary
srec_cat rom.bin -binary -split 4 3 -o U1.bin -binary

You... Do understand that there isn't a whole lot of difference between using a search engine to get someone else's solution... And using AI to explain how you do it?

You're irrational fear of software is really going to cause you issues through your life. "Sorry boss, I can't do my job because I refuse to use software that starts with the letter 'R', or that has green in the toolbar."