25 May
2002
25 May
'02
12:01 p.m.
On May 25, 1:46, Doc Shipley wrote:
First the on-topic. Re: the recent thread about the
ultra-weird PI
SIMMs, I did find some 2M modules, and a shop here will do the chip
conversion to 8M.
Good luck -- let us know how you get on.
Now the off-topic. I'm going to be doing some
testing of a Challenge
S, and will need to do it from a serial console, as it has no graphics
option. The serial port's an RS422 just like a Mac, right?
Nearly. Normally it operates in RS423 (RS232-compatible) mode, although
you can switch it to RS422 mode in software. IIRC the manual says that
both pins 4 and 8 are ground. Don't believe it, use pin 4 (or short 4 and
8 at the SGI end). I've seen several cases of wierd behaviour when people
use pin 8 instead, because pin 8 is really just the -ve differential input
to the receiver, in RS422 mode. To use the first serial line as the
console, you should only need pins 3 (TxD), 4 (SG), and 5 (RxD).
--
Pete Peter Turnbull
Network Manager
University of York