This is the parallel interface only.This interface is also useful for controlling small robots, etc. It is cheap and fairly easy to build, although you should not attempt this project unless you have prior experience with electronics.
Part Total Qty. Description Substitutions
U1, U2, U3 3 74LS367 Buffer IC 74367, 74HC367
MISC 1 Case, Wire, Sockests, 18 Pin Socket (For Output), 25 Pin Connector (For Parallel Port), Ribben Cable
The author built the interface on a piece of universal solder board due to the large number of wires that must cross. It is also much easier to fix mistakes then on a PC board. I also used a 25 pin crimp connector to connect it to the parallel port. 26 conductor ribben cable was used to link the connector to the board. This interface only offers 5 inputs (on some computers it may be less). For more inputs, see Computerize Your Room/House. If you choose to use the inputs, remember that the voltage level can not exceed 5 volts or fall below ground. This circuit is TTL and therefor must be powered by no more then 5 volts.
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