Controlling the World With Your PC by Paul Bergsman is a 1994 hands-on electronics book about using an IBM-compatible PC, especially its parallel printer port, to control and monitor real-world devices. It combines simple hardware projects with working source code in Pascal, C, and BASIC, covering LEDs, displays, relays, audio output, analog voltages, motors, sensors, digital inputs, burglar alarms, and analog-to-digital conversion. It is very much a practical 1990s PC interfacing guide: build the circuit, connect it to the port, run the program, and use the PC as a controller for external electronics.

You can find the source files and executables associated with this book - Here