Over the years, several variations on the original port's design have emerged, yet there has been no single source of documentation that describes the port in its many variations. I wrote this book to serve as a practical, hands-on guide to all aspects of the parallel port. It covers both hardware and software, including how to design external circuits that connect to the port, as well as how to write programs to control and monitor the port, including both the original and improved port designs. If you program in Visual Basic, you can use the routines directly in your programs. I cover the port's original design and the many variations and improvements that have evolved.
Examples show how to design circuits for reliable data transfers.
System troubleshooters can use the programming techniques and examples for finding and testing ports on a system. Experimenters will find dozens of circuit and code examples, along with explanations and tips for modifying the examples for a particular application. Teachers and students have found the parallel port to be a handy tool for experiments with electronics and computer control. Many of the examples in this book are suitable as school projects. And last but not least, users , or anyone who uses a computer with printers or other devices that connect to the parallel port, will find useful information, including advice on configuring ports, how to add a port, and information on cables, port extenders, and switch boxes.