Bruce LeGrande wrote in a message to All:
 BL>    I just obtained several SMC8013WC and SMC8216T NICs,
 BL> and I've noticed that the RJ-45 connectors only seem to
 BL> have 4 conductors active (wired to traces).
 BL>    With the latch at top (pins at bottom) from left to
 BL> right: 
 BL>          0 0 1 0 0 1 1 1
 BL> This would seem to mean that I only need a 4-conductor cable
 BL> for the links.  Is this right ?  And if I just use one cable
 BL> to link (only) 2 of the systems, is the pinning parallel ?
 BL> 1-1, 2-2, 3-3, etc...
In fact, as you discovered, 10Base-T uses only four of the eight pins.  Using 
your diagram above, the pins would be numbered 1 to 8, but from right to 
left. The cabling actually consists of two twisted pairs, one for 
transmitting and one for receiving.  One pair uses pins 1 and 2, and the 
other pair uses pins 3 and 6.  It is important that you not get the pairs 
mixed up.
When you cross-wire two nodes for use without a hub, you cross whole pairs.  
That is, the 1-2 pair is wired to the 3-6 pair on the opposite side, and the 
3-6 pair is wired to the 1-2 pair on the opposite side.  Knowing that the 
pairs are transmitting and receiving should make clear why this is the case.
 BL> ALSO: If anyone has a 4-5 port hub that has been made spare
 BL> by       an upgrade - I'd be interested in giving it a good
 BL> home.           --> needs to work well with the above cards
 BL> <--
You should be aware that these things are widely available new for about $50.
 
-- Mike
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