In article , Chris Merrill wrote: > I'd like to use an A2 to drive some simple digital (TTL) circuitry. The > circuitry would primarily be an interface to sensors, switches and relays. > > I'd like to use a //c, due the small footprint and built-in drive. > However, that seems to limit my I/O options to the serial ports (modem > and printer)...which adds some complexity to the TTL circuitry, compared > to tying directly into a slot in a //+ or //e. > > I've never done this before and haven't programmed an A2 for about 20 > years - so if I can use BASIC with PEEK/POKE, my chances for success > are much higher. > > Any suggestions or good online reference sources? > Apple II in the laboratory A.F. Kuckes & B.G. Thompson Cambridge University Press 1987 ISBN 0 521 32198 Hardware Interfacing with the Apple II Plus John E. Uffenbeck Prentice Hall, Inc. 1983 ISBN 0 13 383844 7 Scientific and Engineering Applications With Personal Computers Raymond Annino & Richard Driver John Wiley & Sons 1986 ISBN 0 471 79978 5 Build Your Own Universal Computer Interface Bruce Chubb McGraw-Hill 1997 ISBN 0 07 912638 3 The Chubb book is probably the best as the hardware interface can work with Apples (including the //c), Macs, Commodores, Ataris as well as PC's. You either build it as a card that goes into a slot or a box that connects to a serial or parallel port. If you can't find these books in the library or a used book store I may be willing to part with them.