A SPARC makes a little fire

Summary

Way back in May of 2018, I was unable to get the SparcStation 1+ to stop returning “Illegal Instruction” errors for any attempt at booting. This made absolutely no sense to anyone I asked about it, and they suggested replacing the PROM battery, because at least then we’d have fewer known-broken parts in the computer. I ignored this advice, and just stuck the computer in a corner with the other broken machines for awhile so it could think about what it did. A few weekends later, I decided to go back and give the little Sun another chance. Perhaps it was the cute pizzabox appearance, or maybe it was that I needed to clear the bench space for something else. To begin diagnosis, I yanked the hard drive out, and discovered the Quantum ProDrive in it was in fact an Apple factory drive. Here’s the badge, indicating that the drive was shipped with an Apple ROM. Looks like it has some pins for a hard drive access LED. Considering it’s a full-height drive, I wonder which Mac this would have come out of. Maybe an early SE or II? Definitely not an LC. A lot of early Apple hard drives are hardcoded to SCSI ID 0, and while they have pins to reset them, they don’t come with jumpers (I realized this was since the three jumpers set the SCSI ID in binary, which should have been obvious to me before - no jumpers = all false = 0). As far as I can tell, this one is the same way. I decided to boot it without a hard drive installed at all. Maybe that would give me a cooler error than “Illegal Instruction!” It did - the computer decided to try and boot off the loopback device instead, and when it failed, it didn’t say “illegal instruction.” What’s more, I could now type boot sd(0,0,0)vmunix without getting Illegal Instruction either! I immediately slammed the drive back in and tried to boot. This time, I just got a SCSI device is not responding error. Assuming the drive was dead, I began my usual Quantum ProDrive diagnostic method of: Feeling the drive for vibrations that indicate it is wo...