PC->AtARI Mouse Adapter
                   ~~~~~~~~~~~~~~~~~~~~~~~

                  Version 1.0 December 1998


Due to the short supply of mice for the Atari computers I decided to
build an adapter that would allow me to use a standard Microsoft
compatible PC serial mouse on my Atari.

           Files in this archive.
           ~~~~~~~~~~~~~~~~~~~~~~

readme.txt	This text file
pcstm010.bmp	Picture of circuit in bitmap format
pcstm010.obj	Object code of the PIC16C84 program
pcstm010.asm	Source code of the PIC16C84 program


When the PC mouse is moved or a button changes state a packet of
serial data is sent, my circuit decodes this data and then simulates
the Atari mouse.

The circuit consists of 2 integrated circuits. IC1 is a RS232 Transceiver
with built in voltage converters. The voltage converters supply the
plus and minus voltages needed for RS232 communication and also power
the PC mouse. IC2 is a microcontroller and contains the program that does
most of the work. The circuit is shown in the file pcstm010.bmp

The PIC16C84 (IC2) needs to be programmed with the PC to ST program.
The program is supplied in two forms pcstm010.obj is an object code file
in Intel hex and can be read by most programmers capable of programming
the PIC16C84, pcstm010.asm is the source code of the program and could be
used with a PIC assembler to generate your own object file.

I've built my prototype on a small piece of stripboard, a picture of it
is on my web site http://members.aol.com/tgkirk/index.htm where it is also
available as a separate download. The stripboard can be mounted in a small
plastic box with the 9 pin male connector mounted on one side. The 9 pin
female connector should be mounted on a short lead with a cover long enough
to reach to the Atari mouse socket.

No special software is required on the Atari and it will work with all software.
Your favourite mouse accelerator program may be used if required.


   Parts list.
   ~~~~~~~~~~~

IC1	MAX202CPE
IC2	PIC16C84

X1	4 MHz Crystal

C1	22 pF
C2	22 pf
C3	0.22 uF
C4	0.22 uF
C5	0.22 uF
C6	0.22 uF
C7	0.22 uF
C8	4.7 uF

CN1	9 Pin D type male connector
CN2	9 Pin D type female connector

Stripboard
 

For further information or if you need a PIC16C84 programmed then
contact me at tgkirk@aol.com  Please allow a few days for a reply
as I have other commitments as well.

		Tom Kirk        Dec 1998

P.S. 	I also have on my web site a PC viewer for Atari format
	picture files.