DEC cables

Paul Koning pkoning at
Wed Aug 24 16:16:36 CDT 2005

>>>>> "Ade" == Ade Vickers <javickers at> writes:

 Ade> Also, not strictly sure if this is on-topic or not, but: I'm
 Ade> planning to install 2 or 3 Cat5e cables from the garage to the
 Ade> house. 1 will be a genuine ethernet; the other two (or maybe 3)
 Ade> I'd like to use as serial cables: If I simply wire them as
 Ade> normal ethernet, will they work OK as serial comms cables; or
 Ade> should I wire them differently? Since I plan to make my own
 Ade> [device] --> [RJ45] and [RJ45] --> [terminal] cables to link to
 Ade> the Cat5e "bridge" cabling, I have complete control over how
 Ade> they are wired up.

Ethernet cable is paired oddly -- it doesn't have pairs attached to
adjacent pins, but the pairs go 1-2, 3-6, 4-5, 7-8.  I remember
someone trying to do an Ethernet link test with a full 100 meter spool
that was wired to adjacent pairs.  Lots of bit errors...

Anyway, terminal links are slow enough that the pairing isn't
critical.  We use Cat5 patch cords here at work for everything,
including UART connections.  It works fine.


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