smb@research.att.com (Steven M. Bellovin) writes:
> I've run RS-232 lines for at least 100 meters, and probably 150.  Mind 
> you, this was back when 19.2 Kbps was fast, but...  Use high-quality 
> cable; the limiting factor is generally the capacitance of the line, 
> which tends to smear the pulses.  And don't be surprised if you can't 
> run at 230 Kbps.

Wow, I guess cables and driver technology has gotten better.  Back
when vt-100's ruled the world there was a crazy communications company
in Cambridge, Mass that had a farm of 10-bit/byte unix boxes located a
few buildings from the engineering lab.  We engineers were stuck using
serial cables that ran the length of 3 buildings; it was only with the
aid of rs-232 to current loop converters at both ends that the damn
things ran at all.  They worked somewhat reliably at 9600 bits/sec and
if you got really lucky and the planets were in conjunction you could
sometimes get 19200 bits/sec to work.  The lines that sometimes worked
at 19.2k were highly coveted for eprom download lines.

-wolfgang
-- 
Wolfgang S. Rupprecht 		     http://www.wsrcc.com/wolfgang/
(NOTE: The email address above is valid.  Edit it at your own peril.)