OT question and On-T info for the SGI crowd

From: Doc <doc_at_mdrconsult.com>
Date: Sat May 25 23:41:32 2002

On Sun, 26 May 2002, Pete Turnbull wrote:

> 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.

  Well, I don't have a Personal Iris, so I won't know. The only reason
I'm in on it at all is that I saw Bob Schaefer's scans of his SIMM and
remembered seeing some like it. Since several folk seemed interested in
the 8M conversion, and I like the folks at MCH, I took a 2M module by
there to see if they could do it.

> 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).

  What a concept - reading the manual for the serial pinouts!
  D'oh!
  I might just build a terminal line from scratch, then. That sounds
like less hassle overall than trying to convert something.

  Thanks,
    Doc
Received on Sat May 25 2002 - 23:41:32 BST