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Suzy B Software 2
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Suzy B Software CD-ROM 2 (1994).iso
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dexx2b
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1995-04-27
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11KB
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256 lines
USING THE LOGITECH MODEL DEXXA 2B (M-M27) SERIAL MOUSE WITH
ATARI 680x0 COMPUTERS (ST/STe/Mega/Mega STe/Falcon/TT)
A good mouse is hard to find for the Motorola based Atari
computers. I've found that the Atari OEM mice just don't hold
up very long and you have to mail order to get one that will
work. I recently ran across some software that allows serial
mice to work with the Atari ST. You can get a pretty decent
mouse for just around $10.00 if you buy the Logitech model Dexxa
2B (M-M27) 400dpi serial IBM PC compatible mouse. This is great
if you don't mind losing your serial port and having to convert
from the DB-9 connector to the DB-25. The best option is to
make the serial mouse work with the ST in the conventional
manner by following the step-by-step procedure that I have
outlined below. If you don't have the time nor the patience to
perform this then ask someone who can or give us a call and we
can help.
WARNING: Custom Design Technology will not be held responsible
for any damage to your computer or any related hardware or
software problems that may be caused by any mistakes that you
may have made or by your inability to properly modify this
equipment. If you have any problems, we are here to help.
It is our option to limit the amount of time we spend regarding
over the phone assistance. We also reserve the option to refuse
assistance if we are busy with our regular business priorities.
Before you run out and buy one of these mice to perform
surgery on, be sure you save the cord assembly from your
ST mouse since you will need it for this one (The original
Logitech mouse uses only 6 conductors and the ST requires 8
total). You might be able to makeup a cable if you can locate
some flexible small diameter 8-conductor cable and a standard
DB-9 female connector. Some soldering experience is required
along with some familiarization with replacing surface mount
devices (SMD).
WHAT YOU NEED
(1). 330 ohm surface mount type resistor.
(2). Phillips screwdriver (not the beverage)
(3). Diagonal cutting pliers
(4). Low-wattage soldering pencil
(5). Solder sucker or solder wick
(6). Needle nose pliers.
(7). Short piece of small gauge bare tin plated wire or similar
(Approx. 1").
Outside from having to replace a surface mount device on the
circuit board, the modification is pretty straightforward.
MOUSE DISASSEMBLY
(1). Rotate and remove the locking plate securing the mouse
ball.
(2). Remove the ball.
(3). Remove the two screws that hold the mouse together.
(4). Carefully separate the two halves of the mouse starting
with the palm end first to prevent from breaking the two
locking tabs at the switch end of the upper shell.
(5). Lift the circuit board assembly out of the mouse proper,
being careful not to break or bend the two plastic
interrupter wheels. Try not to misalign the devices
marked LD1, LD2, LQ1, LQ2. If you do, then it's not too
hard to line them back up again.
(6). Carefully remove the cord "tail" by unplugging from J1 on
the mouse's circuit board. It will make a nice addition
to your junk box.
MOUSE MODIFICATION
(1). With solder wick or sucker, remove the integrated circuit
U1 without tearing up the circuit traces. Clear the holes
of solder using low heat and solder wick. Discard U1.
(2). With the same care, remove the SMD device marked Z1 and
discard.
(3). Remove SMD resistor R3 and discard. It should be marked
with a tiny "390" on it. If necessary, use two soldering
pencils with one on each end of the resistor to remove it.
Clean up the circuit board pads with low heat and solder
wick to prep it for the new resistor.
(4). Install the new 330 ohm SMD resistor at the location marked
R3 and solder. The new resistor should have a tiny "331"
on it.
(5). Familiarize yourself with the proper numbering of the holes
where U1 used to reside. On the component side of the
circuit board you will see a rectangular shaped pattern
with a notch on one end. Hold the board so that the
notched end of the rectangle is facing toward you. Pin
number 1 will be the hole nearest you to the right of the
notch with pin number 16 nearest you to the left of the
notch. You simply count up in a counter-clockwise fashion
around the rectangle.
(6). Fashion the 1" piece of bare wire into the shape of a "U".
This wire is installed on the component side of the board
by first feeding one end into U1's pin no. 10 hole and the
other end into U1's pin no. 14 hole. Leave enough slack in
the wire so that other wires can be soldered into other
nearby holes at a later time. Solder both ends at this
time.
(7). This completes the actual board modifications.
(8). Now it's time to prep the 8-conductor Atari mouse cord.
Cut the cord off right at the Atari mouse strain relief
since the new mouse already has an integral strain relief.
(9). Strip the outer insulation back leaving about one inch of
lead length. Strip each of the 8 wires to leave approx-
imately 1/8" of conductor. Twist the strands together to
keep them from coming apart. Tin the ends of all 8 leads
with solder. These tinned wires must be able to fit into
the holes where U1 used to be.
(10). Take note that NOT all Atari mouse cords have the same
color coding scheme. In the table below I have included
two color code schemes that I have seen in use. If you see
a black wire use color code 1's column. If you see a grey
wire then use code 2's column. Cross out the code column
that does not apply to your mouse cord with a marking pen.
Double check the connections between the keyboard DB-9
connector and the colors against the table below just to be
on the safe side. The best way to do this is with an
ohmeter.
(11). Refer to the wiring chart to solder each of the designated
8 wires of the mouse cord into U1's holes if there are no
discrepencies with your cord. Read step 5 of "Mouse
modifications" again if you have forgotten U1's numbering
scheme.
ATARI ST to DEXXA MOUSE WIRING CHART
DB-9 SIGNAL COLOR COLOR MOUSE
FEMALE DESCRIPTION CODE 1 CODE 2 IC1 Hole No.
------ ----------- ------ ------ ------------
1 --- Horizontal Brown Brown -----> 5
2 --- Horizontal Orange Red -----> 6
3 --- Vertical Green Orange -----> 7
4 --- Vertical Blue Yellow -----> 8
6 --- Right Button Yellow Green -----> 2
7 --- +5 Volts Red Blue -----> 13
8 --- Ground BLACK GREY -----> 9
9 --- Left Button White White -----> 3
(12). Be sure that you DO NOT cross-wire the leads to holes
numbered 9 and 13. Doing so will pretty much toast your
newly modified mouse not to mention the hassles you might
get from the animal rights activists.
(13). All modifications are now complete. Clip off any excess
lead lengths on the foil side (trace side) of the board
and inspect for any solder bridges between adjacent leads
or pads.
MOUSE PRELIMINARY CHECKOUT AND ASSEMBLY
(1). Carefully install the completed board into the lower half
of the mouse and work the cord through the strain relief
channel leaving enough slack in the leads to the circuit
board to keep them from breaking off.
(2). Plug the mouse into the ST and power up making sure that
the power indicator on the computer instantly comes on.
Kill power if you suspect anything wrong and re-check all
of your steps, otherwise, proceed as follows.
(3). Observe the mouse pointer on the display and see if you
can move it both vertically and horizontally by running
your finger along the rollers inside of the ball cavity.
If you can do this, then it's a pretty safe bet that you
can proceed with the final assembly.
(4). Ascertain clearance for upper shell nomenclature by
observing the circuit board wiring etc.
(5). Insert the upper shell locking tabs into the lower shell
tab recesses and close.
(6). Insert the two screws and tighten.
(7). Locate ball and insert into cavity.
(8). Locate the ball locking plate and install. Lock it into
place by rotating in a clockwise direction.
FINAL CHECKOUT
(1). Again check operation. If the mouse pointer moves opposite
the direction of the mouse travel in a vertical direction
then the leads going to U1's hole no. 7 and 8 will need to
reversed. If horizontal movement is opposite, then leads
to hole no. 5 and 6 need reversing.
(2). Check to make sure that the left and right buttons operate
as expected. If they are opposite, then simply swap the
leads to U1 holes numbered 2 and 3.
(3). Check the mouse pointer travel. As you move the mouse from
top to bottom and left to right it should move smoothly
without irratic results. Keep in mind that there is a
limit to the rate at which the mouse can be moved in any
direction without showing signs of irratic movement due to
the limit in speed at which the ST's keyboard processer can
decode the X and Y phases from the mouse. If you feel that
the maximum speed of smooth travel is less than that of the
original mouse then you may need to optimize the alignment
of optical components LD1, LD2, LQ1, and LQ2.
(4). You did it! Yay! Enjoy. Order a pizza.
A WORD ABOUT OUR COMPANY
Custom Design Technology started in 1980 under the name
Christian Computer Products. We started out designing hardware
and software projects for the Radio Shack Color Computer under
the original name. We became more diverse designing and building
several special projects for television stations in our
surrounding area; one of which was an aural telemetry encoder for
television remote trucks. Because of this diversity, we made the
decision to change our name.
Custom Design Technology has always utilized Motorola
products in our designs and continues to enjoy the power and
trouble free performance that their microprocessors provide. We
employ the Atari TT030 exclusively for design and CAD work and
the Hazelwood '020 running Microware's OS-9 for our financial and
record keeping.
If you have a special design request, please call us. We
consider it a privilege to serve you and our Lord and Savior
Jesus Christ in our business.
Custom Design Technology
751 W. Ewing
South Bend, Indiana 46613
Phone: (219) 234-7754
Serving the Broadcasting Industry for over 15 years.