Dual PIA modification for atari 800.

This archive contains the following files:

README				This file
PIAMOD.DOC			Writeup of the mod, Word for Windows 2.0 format
PIAMOD.TXT			Same file stored as ASCII
PIASW.PLD			The source file for the PAL
PIASW.DOC			File generated by the PAL compiler
PIASW.JED			Fuse map for the PAL

This mod is a description of how to fit a second PIA onto an Atari 800, so as
to get around the problems caused by the change in function of the original
PORTB between the 800/400 and the XL series.

The PAL file is written to be compiled with CUPL, but it's fairly simple and
should not cause any problems to convert to another PLD compiler.

The .JED file is the one you need to send to the programmer.

Note that this mod will do nothing if fitted to a stock 800, it's intended to
work with machines that already have extended RAM and an OS switcher fitted.