PS/2 Mouse To Amiga Converter
                        =============================


current version: V1.0 (30-Jun-2001)
~~~~~~~~~~~~~~~~


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  DISCLAIMER  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                              ------------
    The circuit diagram here is provided "as is".  I do not take any
   responsibility for any damage caused by use of the hardware or the
  information presented here.  Using this is entirely at your own risk!
                                                         """"""""""""""
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



Legal:  This is classified as FREEWARE.  You are allowed to build it and
~~~~~~  use it but you are not allowed to commercially exploit it.  If
        you distribute it please include the whole archive.  If you`ve
        built it I would very much appreciate some feedback via
        postcard or e-mail.



What is this:  This is a simple hardware converter, utilising PIC16F84
~~~~~~~~~~~~~  microcontroller,  that allows you to connect a standard
               PS/2 mouse to your Amiga mouse port.  It doesn't need
               any software drivers in order to run, just plug the
               converter into your mouse port and a PS/2 mouse into
               converter and off you go!  No modifications are needed,
               neither to mouse nor to Amiga.  As far as Amiga is
               concerned, it won't even know it is not the genuine
               Amiga mouse that is connected to it's port.



Requirements:  - an Amiga (any model, any Kickstart)
~~~~~~~~~~~~~  - a PS/2 mouse
               - this converter




Hardware description:
~~~~~~~~~~~~~~~~~~~~~

         The heart of the converter, a PIC16F84 microcontroller, does
         all the job.  It receives serial data packets from PS/2 mouse
         and after conversion outputs standard Amiga H, HQ, V, VQ
         movement information and three mouse buttons' status to
         Amiga mouse port.  It does not support the 4th and 5th button
         nor the additional scroll wheels found on some fancy PC mice.
         Such mice will be recognized and used as standard PS/2 mouse
         with only standard movement and two or three buttons.

         Oscillator in the PIC chip is configured as RC type.  With
         27pF capacitor and 4.7kohm resistor it will oscillate at
         around 3.4MHz.
         10kohm pull-up resistors on PS/2 CLOCK and DATA lines wouldn't
         be necessary if PIC PORTB pins were used for DATA and CLOCK
         because of PIC's internal pull-ups, but...  two resistors
         won't take too much space, especially if you use SMD :)
         The only other parts are 100nF capacitor for decoupling,
         9pin SUB-D socket and 6pin MiniDIN socket, and, of course, a
         printed circuit board, which can be made pretty small.

         Circuit diagram found in this archive is also PCB layout
         suggestion.  I'd recommend you to remove the metal plating
         from the front (coupling) side of the SUB-D socket, as it is
         not needed anyways, and you won't have to be careful not to
         short any pins with it when coupling the socket with Amiga
         mouse port plug while Amiga is on.

         Of course, PIC chip must be programmed before you can use it.
         ps2mouse.hex is the program in IntelHex format and
         ps2mouse.asm is the source code.  When programming the PIC,
         you should set oscillator type to RC, WatchDog Timer to OFF
         and Power-On Timer to ON.  If you don't have a PIC programmer
         yet, there are many PIC programmer projects on Internet or
         Aminet (search for APIC, devpic, pickit, Epic...)

         In case your mouse freezes, simply unplug the converter from
         Amiga mouse port and plug it in again.  This will reset the
         mouse and the converter.  It could have been made to cycle
         mouse power automatically, but I've found it unnecessary.
         I've tested it with some very cheap chinese made mice quite
         a lot and I use it for a long time and never once had a
         mouse freeze, it works perfectly.


I can't guarantee it will work with any PS/2 mouse (it should, because
it's a standard, but who knows).  It works fine for me.

So far I tested it on my:

               A1200 KS3.0
               8MB 60ns Fast RAM board with 68882 FPU and RTC
               IBM 280MB IDE HDD
               Commodore 1084S Monitor


               A500 KS1.3
               A501 SlowFast RAM board (connected as CHIP RAM)
               external DD floppy

It was tested with some really cheap chinese made mice.  No problems
were experienced, so it seemed unnecessesary to include mouse reset by
cycling mouse power off/on.  If you find it necessary, contact me and
I'll include it in the next version.


Author:
~~~~~~~
              e-mail:  nogoth@yahoo.com


              N. Baricevic
              Sunekova 5
              10040 Zagreb
              CROATIA


                  If you've built this converter and use it,
              please send me a postcard or e-mail me.


   The latest version can be found on my web page:

                     www.geocities.com/nogoth




Included in this archive:
~~~~~~~~~~~~~~~~~~~~~~~~~

         - ps2mouse.txt  -  this file
         - ps2mouse.iff  -  circuit diagram (IFF format)
         - ps2mouse.png  -  circuit diagram (PNG format)
         - ps2mouse.hex  -  PIC16F84 programm in IntelHex format
         - ps2mouse.asm  -  PIC16F84 programm source code