iBook G3: Where is the Open Firmware chip?

[YesWeCat]

So I have a spare iBook G3 logic board, and what I want to do is read the contents of the Open Firmware ROM with an EEPROM flasher. But I have been trying for a while to guess which one of the dozen or so EEPROM chips is the one that actually contains the Open Firmware ROM.

Does anyone have an idea of which chip is it?

 

[timidpimpin]

I'm a former Mac tech, and I'm not even sure. You'll need to find a board schematic.

 

[LightBulbFun]

it will be a relatively large (compared to a normal EEPROM) 40 pin TSOP chip in a rectangular package its a parallel flash chip not a SPI one so your going to need a different hardware flasher sadly

out of curiosity what do you want to dump it for? @dosdude1 has made a patched version of flashrom for PPC Linux that can Read and write the BootROM EEPROM of the PPC mac its running on

 

[YesWeCat]

it will be a relatively large (compared to a normal EEPROM) 40 pin TSOP chip in a rectangular package its a parallel flash chip not a SPI one so your going to need a different hardware flasher sadly

out of curiosity what do you want to dump it for? @dosdude1 has made a patched version of flashrom for PPC Linux that can Read and write the BootROM EEPROM of the PPC mac its running on

Very interesting! Do you have any link at hand?

What I am trying to do is dump the Apple Open Firmware ROM and mess a bit with it, looking for strings on it and comparing it with Mitch Bradley's x86 implementation I run on another computer, since it is known that Apple's implementation is very different.

 

[timidpimpin]

Looking back on my certified Apple repair days... the one real shortcoming is that they never teach you how to actually fix a part, even back in the 90's when I started. All you ever learn is system disassembly and part replacement. People like Louis Rossmann and @dosdude1 are so far above what any Mac tech can do.