with this book I learned about SW/HW interfacing with 6502 ~ "Programming & Interfacing the 6502, with Experiments", Marvin L. Dejong ~ http://www.amazon.com/Programming-Interfacing-6502-Experimen... A review can be found here ~ http://www.atarimagazines.com/computeii/issue2/page21.php
There are plenty more references here ~ http://www.6502.org/books
with this book I learned about SW/HW interfacing with 6502 ~ "Programming & Interfacing the 6502, with Experiments", Marvin L. Dejong ~ http://www.amazon.com/Programming-Interfacing-6502-Experimen... A review can be found here ~ http://www.atarimagazines.com/computeii/issue2/page21.php
There are plenty more references here ~ http://www.6502.org/books