Encoders

Hi,

In a previous post I mentioned that I have acquired a couple of old
plotters - well, one of them is now less than its previous self and the
motors, controller etc., are sitting on the bench in front of me.
The encoder bit of the motors has a 10-way ribbon cable coming from it and I
have attempted to trace the wiring - not too successfully. There appear to
be 4 black wires which are all connected together electrically (as far as I
can see with my ohmmeter) which I presume are groungs, 3 red wires which are
also electrically connected which I assume are +5v (I know these are
connected to the LED which shines through the encoder disk via a 120 ohm
resistor). There are also 3 other wires, brown, white and green which I
assume are the outputs. On the small PC-board inside the encoder I can see
through plated holes marked A+, A-, B+, B- but I can't trace where they are
connected to as they dissapear under the encoder disk, they certainly aren't
connected directly to any of the output wires.
So, without having any 'serious' test equipment, is there any way I can
determine what the various wires do and what the encoder count is (for
preference without having to take the encoder disk off and count the lines
by eye!) ? If it's any help, the colour sequence is:-
brown, red, white, red, black,black,black,black,green, red.
Thanks,

Ian
--
Ian W. Wright
Sheffield UK
www.iw63.freeserve.co.uk