How to make an 8 channel control cable from an old parallel printer cable

Have one of these laying around?

You can use it to control 8 SSRs to turn on and off lights.
I used one to run the float in the parade of lights.

Here's how you do it.

1: cut off the end that connected to the printer (with the funny "bar" in the middle shown on the right side of the above image.)
2: find pins 2, 3, 4, 5, 6, 7, 8 and 9 . These are the data pins.
3: find pins 18, 19, 20, 21, 22, 23, 24 and 25. These are the ground pins.

4: Now, using an electric meter, test continuity from the pins to locate the wires they are connected to.
5: on your Solid State relays, connect the ground to the relay ground, the data pin to the relays control, and connect power accordingly.
If you don't have Solid State relays, see my tutorial on how to make your own.