CPU / Boot PROM

This page collates whatever boot firmware and CPU bootstrap PROM images I’ve found or dumped as part of SGI work.

Indy

These are (ST)93CS56 8 pin EEPROMs in 16 bit mode. They are used to bootstrap the CPU during power-on.

The datasheet for this part is available here:

• ST93CS56.PDF - ST93CS56 datasheet

And the CPUs:

• r4600pc-133.bin - R4600PC-133 CPU PROM
• r5000pc-150.bin - R5000PC-150 CPU PROM