🚀 go-pugleaf

In <1993Jan27.041554.6018@ringer.cs.utsa.edu> senseman@lucy.brainlab.utsa.edu (David M. Senseman) writes:

| Just out of curiosity, where is "sysinfo" physically located
| in an Indigo? The reason I ask is that I kind of expected 
| a copy protection scheme that uses "sysinfo" to break when
| I swapped out my R3K cpu board with a R4K cpu board (and 
| power supplies). Suprisingly it didn't seem to affect the
| copy protection scheme :)

Presumably you mean the information *used* to generate the contents
that sysinfo prints?

It is based on different things on different systems, but frequently
(not always) on the the ethernet address.  The ethernet address comes
from the NVRAM (initially, and the sysinfo info is generated at boot
time, so later changes to the ethernet address don't affect it).

On Indigo, the nvram is physically located on the backplane.
(It is actually a serial EEROM for Indigo, and the 20,25,30, and 35;
it is a socketed 8 pin DIP package).

On the 20-35, it is on the PC board with the power switch; that is
why the ribbon cable from the E-module to that board has so many
conductors.

On most of the ASD (power series and IP4) systems, it has traditionally
been battery backed RAM on the I/O board.

On systems with PROM passwords, you have to remove the nvram chip
or the battery for the ram to defeat the password (which is OK, since
if you have physical access, the prom password is meaningless).

The new Indigo2 has the same nvram on the i/o connector board, but
has a jumper to bypass the prom password.  I'm not sure what Onyx
has done.
--
Let no one tell me that silence gives consent,  |   Dave Olson
because whoever is silent dissents.             |   Silicon Graphics, Inc.
    Maria Isabel Barreno                        |   olson@sgi.com