May 13, 2025

Sun 3/60 -- IDPROM and EEPROM

First of all, we don't have NVRAM -- that is/was battery backed SRAM integrated with a clock calendar. It was used on sparc machines and as far as I know the only sun3 that had it was the 3/80.

We do have a 32 byte IDPROM, which is immutable.

Much of the online information confuses the IDPROM, EEPROM, and NVRAM.
What seems to be most common is to refer to EEPROM as IDPROM, never mind NVRAM, which is irrelevant to use outside of the 3/80.

If you type 'q' to the bootrom, it will show you EEPROM bytes (and let you change them).

I have a Sun 3/E in hand. It has a SEEQ PQ2816A chip, which ought to be the 2K by 8 EEPROM.
I see the same chip on a 3/160 board.

The 3/160 board has a tiny (16 pin) chip at location U1409 which is the IDPROM.
I'm not going to scrape off the label (which is 3 10922) to see the part number, but no doubt it is some bipolar OTP rom.

IDPROM layout

We have 32 bytes, like so: 
Byte 0 -- format
Byte 1 -- machine type
Byte 2-7 - ethernet address (6 bytes)
Byte 8-11 - date (4 bytes)
Byte 12-14 - serial number
Byte 15 - checksum
Byte 16-31 - reserved (unused)