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-
- PREFACE
- =======
-
- The following text has been written in 1998 by Stephan Rupprecht
- and explains how to modify a serial mice to work on the Amiga.
-
- IMPORTANT: If this modification causes any damage to your
- computer, mice or any other pet;), I am NOT responsible. And
- don't forget: if you have a new mouse, you'll loose warranty!
-
- Being sick of the "good" old C= mouse and having a serial mice
- "flying around", I decided to modify this mouse to work on
- my Amiga. So I took a look at several texts found on the Aminet
- which described the modification of such a mouse. Unfortunely
- this didn't work for my mouse as it is a bit different to those
- described.
-
- WHAT YOU NEED FOR THE MODIFICATION
- ==================================
-
- Some experiences in soldering and the tools to do it ;)
-
- 1x LM339 Quad Voltage Comparator IC (= TDB0139 = LM239)
- 1x 150Ohm Resistor (1/4 or 1/10 Watt)
- 1x 5+1 10k Resistor Network (or 4+1 10k and a single 10k one)
- 1x 5+1 2.7k Resistor Network (or 4+1 2.7k and a single 2.7k one)
- and some 9pin cord with a female db9 plug.
-
- COSTS: about US$ 5.-
-
- NOTE: Please read the following text before you buy anything, you
- might need different resistors!
-
- HOW IT WORKS
- ============
-
- First disassemble the mouse and disconnect the mouse cord.
- Second remove the 16pin integrated circuit and clean out
- the holes as we need them to solder in the new mouse cable.
- Now follow the trace that is connected to the negative terminal
- of the small electrolytic (C1) capacitor, the trace should end at
- the cable socket (CN1). This is GND. Connect line 8 of your new
- mouse cord to it. Go back to C1 and follow the trace that is
- connected to the positive lead of C1, it should also end at CN1.
- This VCC (+5V), connect line 7 of your mouse cord to it.
- (Alternatively, you can use a voltmeter to find the correct lines,
- for this purpose your mouse must be connected to the serial port).
- After doing this, take a look at the switches for the mouse-buttons,
- and check if they're connected to VCC or GND. In case that
- they're connected to VCC, you've to disconnect them from VCC and
- connect them to GND. Now follow each trace that goes from a switch
- to one of the holes where we removed the IC before and solder in
- the appropiate line of your mouse cord to it: line 6 of the
- mouse cord must be connected to left button, line 5 to the
- middle one and line 9 to the right one. As your mouse might
- differ from my one (BTW: it's a Genius EasyMouse), you've to
- check the following: pin 1 and 3 of each ir-detector should be
- connected to GND via a resistor (normally named RP1). If not,
- connect the input line of your 5+1 (or 4+1) 2.7k resistor (marked
- by a point) to GND and the output lines of the ir-detectors
- (pin 1+3) to the resistor (watch out for a group of five holes
- named RP1 - this is the right place for the resistor). Please note
- that we'll also connect these lines to the LM339 IC! If you're a
- lucky one because the output lines are already connected to GND,
- just remove the old resistor (RP1) and replace it by the new
- (2.7k) one (you'll probably need a 4+1 instead, but don't forget
- to buy an additional 2.7k resistor then).
-
- +-----------+
- |ir-detector|
- 1 2 3 +---------------+
- +-----+-----+ |2.7k resistor °|
- | | | +--+--+--+--+---+
- | | | | | | | | |
- | | | | | | | | |
- | | +--+ | | | | |
- | ° | | GND
- | VCC | |
- +-----------------+
- | |
- | |
- to LM339
-
- Next we've to connect the following lines to the LM339: Connect
- pin 1 of the vertical ir-detector to pin 5 of the LM339 and pin 3
- to pin 11 of the IC. Pin 1 of the horizontal ir-detector must
- be connected to pin 7 and pin 3 to pin 9 of the LM339 (simply
- solder a wire from the IC's holes [the holes that are connected
- to the detectors] to the LM339).
-
- Now connect pin 3 to VCC and pin 12 to GND. Pin 4,6,8 and 10
- must be connected to +1V: Connect one (free) line of the 5+1 2.7k
- resistor to one (free) line of the 5+1 10k resistor (which must
- be connected to +5V). This new line, just created, will give you
- the +1V needed for the comparator.
-
- °VCC °VCC
- / /
- \10k \10k +---------+--------+
- / / | | |
- | | - VQ-Pulse|HQ-Pulse | |
- Line3+ L.4+ --- IN | IN | |
- OUT| OUT| | | | | | | VCC
- +----|----|----|----|----|----|----|----+ | °
- | 14 13 12 11 10 9 8 | | /
- | | | \ 10k
- +- | | /
- | | LM 339 | +---+
- +- | | \
- | | | / 2.7k
- | 1 2 3 4 5 6 7 | | \
- +----|----|----|----|----|----|----|----+ | ---
- | | | | | | | | -
- Line1+ L.2+ ° | V-Pulse | H-Pulse |
- OUT| OUT| VCC | IN | IN |
- \ \ | | |
- /10k /10k +---------+-------------+
- \ \
- °VCC °VCC
-
- Finally, pin 1,2,13 and 14 (LM339) must be connected to
- VCC through the 5+1 10K resistor. When you've done this,
- connect pin 1 to line 1 of the mouse cord, pin 2 to line 2,
- pin 14 to line 3 and pin 13 to line 4. That's all,
- almost;) Replace R1 (this should be the limiting
- resistor for ir-light emitters) through the new 150Ohm
- one. IMPORTANT: The leds of your mouse might differ, so
- better try a stronger one before using the 150Ohm one!
-
- TROUBLE SHOOTING
- ================
-
- The mouse buttons don't work:
- You've forgotten to disconnect them from VCC and connect
- them to GND. Check the lines!!!
-
- The mousepointer is moving into the wrong direction:
- you've swapped the horizontal or vertical lines.
-
- The mousepointer doesn't want to move:
- 1) Check for around 0.5V at pin 5,7,9,11 of the LM339.
- 2) Pin 4,6,8,10 of the IC should get +1V. Pin 3 is VCC and
- must get +5V.
- 3) The limiting resistor for the leds is too strong, use
- a smaller one.
-
- The mousepointer moves only up/down or left/right:
- The resistor for the leds is still too strong, try a smaller
- one.
-
- FINAL NOTE
- ==========
-
- Normally, the V and H pulses that are produced by the ir
- detectors should be around 0.5V. As this wasn't enough
- to work with my mouse (I used a 330Ohm resistor for R1),
- I powered up the ir-leds by using an 150Ohm resistor. Now
- the ir-detectors output up to 2V for a movement, this works
- for me but it doesn't mean that works for you! You should
- also try different resistor combinations, eg. use a 330Ohm
- resistor for R1 and lower the voltage of the comparator
- circuit from 1V to 0.3V (= used by the original C= mouse).
- You could also try to powerup the ir-detectors, so that
- they output upto 5V for a movement. This way you won't
- need the LM339 and the 10k resisitor!
-
- CREDITS
- =======
-
- I would like to thank the following people
-
- Gene Heskett (genes_pc_mouse.lha),
- J. Edward Hanway (optmouse12.lha),
- Jeff Easton (mousehack.txt)
-
- for writing down their serial mouse hacks.
-
- AUTHOR
- ======
-
- Stephan Rupprecht
- Apfeldweg 1
- 44359 Dortmund
- Germany
-
- stephan.rupprecht@primus-online.de
-