ABSTRACT
This chapter describes a board that uses a safe input/output (I/O) interface for a personal computer (PC) parallel port. It examines cabling and necessary software components for PC to PC serial communication. The parallel port of a PC uses transistor-transistor logic (TTL) signals. A TTL logic chip accepts voltage levels from 2.0 V and higher to be considered a logic “high” signal, and any voltage below 0.8V to be a logic “low”. The Baud rate is set to 2400 with the TTL True mode. The bottom breadboard has the circuit for parallel port output interfacing with the light emitting diodes and the top breadboard has the 5V power generation from a 6V alternating current adapter. Serial port is used for transferring data serially as compared to the parallel port that is used for parallel transfer of data.
