I am about to make two part (tx and rx) device to identify the
 wires in multi conductor cable

 I know this has been done before (Electronics No.45 is one)
 but most require a common ground wire

 I plan to use a + pulse of 1*n where n is the wire number
 all the other connectors are grounded for the duration so
 the system should work without a common ground,
 enabling me to pick any of the conductors as a ground

 For the TX I will use a 16c84 with twelve (maybe I'll use a
 16c55 later and use 16 or 20 pins) port pins via 330
 ohm resistors and croc clips to the wires to be identified

 The RX also a 16c84, portb to a two digit led
 RA4 and ground will connect via croc clips
 to two of the multi conductor cables
 the led's will display the cable number that
 RA4 is connected to

 I would be interested to hear if anybody can see a better
 or novel method of doing this job

 Peter Cousens
 email: peter@cousens.her.forthnet.gr  phone: + 3081 324450, 380534
 snailmail:  Folia, Agia Fotini, Karteros, Heraklion  Crete, Greece.