This is a great little project book with several useful projects and exemplar code showing how to access the BBC Micro's User Port to which the hardware projects are intended to be connected. The information in this book has proved invaluable when developing my graphing software that interfaces with the VELA Versatile Laboratory Aid by Educational Electronics.
The book contents covers dealing with Hexadecimal and Binary notation, interfacing with the BBC Micro's User Port using the memory range called "Sheila" followed by a detailed theory of operation of the second 6522 VIA. The book goes on to cover operating system safe ways of accessing "Sheila" to build second processor safe applications before moving on to the hardware projects themselves which include:
For further information about this book, you can search the Internet using the following ISBN number: 0201145030