Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!venera.isi.edu!nomdenet
From: nomdenet@venera.isi.edu (A. R. White)
Newsgroups: comp.sys.ibm.pc
Subject: Maximum Length of Cables for Parallel Port?
Keywords: Parallel-cable lengths, A-B-C switch boxes
Message-ID: <11428@venera.isi.edu>
Date: 17 Jan 90 03:20:06 GMT
Reply-To: nomdenet@venera.isi.edu (A. R. White)
Distribution: na
Organization: Information Sciences Institute, Univ. of So. California
Lines: 27


   This inquiry is for a friend who wishes to connect two PC/AT clones
to a laser printer.  He would like to leave the machines where they are,
which leads to my first question:  How long may cables for the parallel port
be, both as specified in the standard (whatever that may be) and as found
workable in practice?  What are the signal-degradation mechanisms?  Cross
talk?  Smearing of pulses due to cable capacitance?
   Clearly both clones can't be connected to the laser printer at the same
time, which leads to another question:  Can anybody recommend good parallel-
port A-B-C switch boxes?  Would any box with DB-25 connectors suffice;
or do boxes designed for RS-232 applications do something funny with the
grounds, which could be remedied with a screwdriver and wire cutters?

   Please reply directly to me; I don't follow this group.


Thanks,

A. R. White
USC/Information Sciences Institute
4676 Admiralty Way
Marina Del Rey, California
90292-6695 
(213) 822-1511, x162
(213) 823-6714  facsimile

ARPA:  nomdenet @ ISI.edu