David Johnson wrote: > Normally during boot a basic test is run, but if you Stop-A into the PROM > itself you can manually run a more thorough memory test, although I forget > how (probably 'test memory' or similar depending on PROM version). > > Although only the larger servers have a keyswitch, all systems (AFAIK) have > a 'diag-switch?' PROM variable which you can set to true to make the system > run more advanced tests automatically when booting.
The SS1000E I've got here effectively has two completely different programs in its PROMs- the first (lower in memory, probably written by Xerox) is custom C code which provides detailed configuration and test facilities for each board, the second (higher in memory, written by/for Sun) is the Forth runtime and custom routines which comprise OpenBoot. Unless the key is in the diag position (I don't believe that diag-switch? is relevant here) you can't get into the former and see no indication that it's being run, but once you're into it you can see things like JTAG device IDs and- I think- the final stage where the multiple system boards are merged into a single computer before OpenBoot runs. I don't know how much of this was carried forward to later machines, but I'm hoping to get my hands on an E4500 (in uncertain condition) before too long. -- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
