Ethernet Cables?

[gordonjcp at gjcp.net]

>
> I found a couple of cables with the cable checker and have not been able
> to find out what these things are. Both ends are terminated with RJ-45
> connectors, and the cable checker has pins 1 & 8 (blue/black) and 2 & 7
> (yellow/orange) shorted together. They have a tag labled "IBM P/N
> 58X9806". One of them has a date of March 1990; anyone know what these
> things are used for? Thanks!

Almost certainly Token Ring over CAT5 cable.  I checked the part number
since I'm at work at the moment, but it turned up nothing - but that may
not be the actual part number (AIUI there is an assembly p/n and an FRU
p/n, and our parts checker only works for the assembly one.  And possibly
for a limited range of parts at that.)

Gordon.