[rescue] SGI Indy questions

[James Lockwood]

On Sun, 12 Jan 2003, Jonathan C. Patschke wrote:

> On Sun, 12 Jan 2003, Curtis H. Wilbar Jr. wrote:
> > I see a 1 and 2 port (are these serial?)
>
> Yes.  RS-422, like a Macintosh.

The Mac does not use RS-422, despite lying documentation.  It uses
differential RS-423 which is compatible with RS-232/EIA-232D under
favorable conditions.  It's also more or less compatible with RS-422,
under good conditions with a favorable wind and high-quality RS-422
receiver chips that won't blow out when exposed to higher-than-spec
voltages.

Had Apple used RS-422, you would not be able to connect RS-232 devices.
Period.

SGI used RS-423 on the Indy.

-James