A timely book on a friendly subject, MIDI Projects is a practical book principally concerned with interfacing synthesisers to your computer.
In addition to this, the book considers the development of MIDI and fills in a lot of background knowledge which confuses newcomers to this recent development in the musical world.
MIDI stands for Musical Instrument Digital Interface. A MIDI allows you to program an instrument to play by itself controlled by the computer.
The book shows how to construct and modify an all-purpose interface for a wide range of computers including the Spectrum, QL and humble ZX81. The circuit is built around a general purpose 6402 UART chip (Universal Asynchronous Transmitter/Receiver). The text is detailed but gives no combat to non-technical people. This is acceptable because the area of computer interfacing of any type should not be tackled unless you understand a little about what you're attempting to do. Blowing your computer via the expansion port is a short cut to an expensive repair bill.
The final section of the book dabbles in the circuitry required to drive any instruments based on the MIDI's predecessor, the CV system.
For a home constructor bent on saving a few quid this book is well worth a browse. The only qualms that I have is that of software compatibility. What good is an interface link without anything to drive it?
Penfold's style is easy to follow and the book is well worth considering, especially at the price.