In this case I don't want to write new boot code for this poor old piece of hardware. In fact my Sun-4/110 boards just went to the scrap yard, but before I sent them on their way I harvested a few socketed parts, including the boot roms. The Sun-4/110 is a particularly unexciting piece of hardware seing as it did not support the VME interface and was basically what it was and never any more. I have Sun-4/300 that I keep to let me fiddle with ancient VME hardware until I get bored with that and send it all to the scrap yard, but I digress.

Ultimately these EPROMS will be erased and reused, but it might be interesting to pop these into the prom burner, read them out and then go through the exercise of disassembling them and studying the code. This gets a person involved in a giant tangle of potential legal issues. As a hacker hobbyist, I am interested in this from a purely intellectual point of view. I do have to at least sound the warning that this may or may not be smiled upon by our current legal climate, sad though that may be.

There are four proms (each prom is 8-bytes wide, but the SPARC will only read 32 bits at a time) used to provide a 32 bit wide memory path. It would be easier in some ways to actually boot up the sun 4/110 and just let it read out the EPROM address space 32 bits at a time, but since I have pried the chips out of their sockets and sent the boards to the recycler, this is no longer an option.

Once I read out the 4 eproms, I will need to write a program to collate the bytes and emit a single file in some format. The format will be determined by the next stage, which is feeding said file to some kind of disassembler. Stay tuned.