The PROWLER DIY section


                 How to Convert a 2600 Driving Controller into a
                       Rotary Controller for Tempest 2000
                                       by
                                 Kenneth Sumrall
				 ken@cup.hp.com
                       ==================================

First of all, I'd like to thank the following people for posting info on rotary
controllers they've built, since they helped me make my own rotary controller:
     Uwe Roeger (uwer@aragon.bb.bawue.de), for posting a schematic of the
       jaguar controller.
     Andrew Hague (andrew@minster.york.ac.uk), for posting schematics for
       using an Atari ST mouse for a rotary controller.
     Andy Light (alight55@aol.com), for his instructions on making his own
       rotary controller.
     Ben Johnson (benjohnson@aol.com) for his suggestion to use a momentary
       toggle switch mounted in a 2600 Driving controller, and also for
       the suggestion to mount a DB-9 jack in the Jaguar controller to
       interface to the rotary controller.  He also suggested adding lead
       weight to the controller to make it spin better.


These instructions are broken down into three parts, part 1 describes the
modifications to the Jaguar controller, part 2 describes the modifications to
the 2600 Driving controller, and part 3 describes how I added lead weight to
the rotary controller to improve its spin.  The driving controller will still
work on the 2600 Indy game after performing these modifications.


The following connection table is used in the first two parts of the
instructions.  It briefly describes the connection of the the DB-9 jack to the
Jaguar controller, and the wiring of the additional switch on the 2600 Driving
Controller.

+-----+---------------+---------------+---------------+-----------------------+
|     | Rotary        | Sega cable    | Jaguar        | Jaguar                |
|DB-9 | connection    | color         | function      | connection            |
+-----+---------------+---------------+---------------+-----------------------+
+-----+---------------+---------------+---------------+-----------------------+
| 1   | right side    | Brown         | Right         | Ribbon cable 2        |
|       encoder       |               |               |                       |
+-----+---------------+---------------+---------------+-----------------------+
| 2   | left side     | Red           | Left          | Ribbon cable 12       |
|     | encoder       |               |               |                       |
+-----+---------------+---------------+---------------+-----------------------+
| 3   | B switch      | Orange        | B             | DB9 connection to 4148|
|     |               |               |               | Anode, Cathode to Jag |
|     |               |               |               | controller pin 3      |
+-----+---------------+---------------+---------------+-----------------------+
| 4   | C switch      | Yellow        | C             | DB9 connection to 4148|
|     |               |               |               | Anode, Cathode to Jag |
|     |               |               |               | controller pin 2      |
+-----+---------------+---------------+---------------+-----------------------+
| 5   | B/C common    | Green         | Keypad B      | IC pin 4              |
|     |               |               | and C row     |                       |
+-----+---------------+---------------+---------------+-----------------------+
| 6   | Button A      | Blue          | A             | Ribbon cable 5        |
+-----+---------------+---------------+---------------+-----------------------+
| 7   | N/A           | Grey          | +5V           | IC pin 20             |
+-----+---------------+---------------+---------------+-----------------------+
| 8   | Encoder       | Black         | Left/Right    | Ribbon cable 1        |
|     | center and    |               | column enable |                       |
|     | button A      |               |               |                       |
+-----+---------------+---------------+---------------+-----------------------+
| 9   | N/A           | White         | Ground        | IC pin 10             |
+-----+---------------+---------------+---------------+-----------------------+

One last thing before you start, these modifications worked for me.  If they
don't work for you, you're on your own.  I can't accept liability for any
damage you do to your system/controller/yourself.


Part 1: Adding a DB-9 connector to your Jaguar Controller.

  Parts needed:
  1) DB-9 male connector
  2) Lots of 30 AWG wire wrap wire
  3) Two 1N4148 diodes
  4) Two 4-40 screws, with lock washers and nuts

  Tools needed:
  1) An exacto knife to remove the rubber caps over the screws.
  2) A number 1 Phillips screwdriver.
  3) A low wattage soldering iron with a small tip.
  4) Some contact cement.
  5) A tool to cut a mounting hole in the Jag controller case.
     I used a Dremel tool to cut the hole, and a drill press to
     drill the mounting screw holes.

  A good supply of patience is also recommended.

1.  Carefully remove the 4 rubber caps on the back of the Jaguar controller.

2.  Remove the 4 screws holding the controller together.

3.  Remove the 2 screws holding the circuit board to the case.

4.  Remove the circuit board.

5.  Cut a hole in the center bottom part of the back shell of the controller.
    This is where you will put the DB-9 connector.  This is probably the
    hardest part of the project.  Once the hole is cut, put the DB-9 connector
    in place, and check for proper fit by putting the two empty pieces of the
    shell together.  If things don't fit, file them down until they do.  I
    actually had to file down a small piece of the DB-9 connector I used.
    Be careful, but be creative.

9.  Drill the two mounting holes for the DB-9.  Make sure everything fits.

10. Using the wire wrap wire, solder nine connections using the left most
    and right most columns in the table above.  The DB-9 pin numbers are
    usually marked on the connector itself.  Look closely.  You may need to
    use a magnifying glass.

    The pin numbers for the ribbon cable refer to the cable that connects
    the joypad circuit board to the main circuit board.  I numbered them
    from 1 to 13, with the number one wire near the outside of the board.

    The IC's pins are numbered in the standard way.

    The connections DB-9 pins 3 and 4 may need a little extra explanation.  You
    should hook up the Anode of the diode to the DB-9 connector, and the
    Cathode to the controller circuit board.  I don't know if these diodes are
    strictly necessary or just a protection measure, but I'm just copying parts
    of the circuit diagram of the original Jaguar controller.  The connection
    to the jaguar port pins 2 and 3 was made where the cable attaches to the
    board near the the IC.

    The power pins are not needed to use the 2600 driving controller, but if
    you ever want to add a controller that needs power, you won't need to
    rewire your Jaguar controller.

11. Once everything is connected, mount the DB-9 connector to the rear shell,
    and screws the controller board in place.  Now test all the connections you
    wired, and check for shorts between pins that you soldered.  If everything
    checks out OK, carefully put the two halves of the shell together, making
    sure you don't pinch any wires, and screw the case together.

12. Using contact cement, carefully glue the rubber pads back in place.





Part 2: Modifying the 2600 Driving Controller for use with Tempest 2000

  Parts needed:
  1) Genesis joypad extension cable (about $10 at Electronics Boutique).
  2) Small SPDT Momentary-Off-Momentary switch.  I ordered my switch
     from Digi-key, part number CKN1088-ND, for $6.78.  It is by no means
     the only switch that will work, but it was small, and easily obtainable.
     Digi-Key's phone number is (800) DIGI-KEY.  I am in no way affiliated
     with Digi-Key.  BTW, if you order less than $25 of stuff from Digi-Key,
     they will tack on a $5 processing fee for the purchase.

  Tools needed:
  1) Drill
  2) Wire cutters and strippers.
  3) Exacto knife.
  4) Small wrench to tighten switch mounting nut.
  5) Soldering iron.
  6) #2 Philips screwdriver

1.  Remove the 2 screws holding the 2600 controller together.

2.  Unplug the switch from the wires attached to it.

3.  Unsolder the three wires attached to the shaft encoder.

4.  Throw away the old cable.

5.  Cut off male connector (Ouch!) from the Genesis extension cable.

6.  Using the exacto knife, cut back 2 inches of the outer insulation
    exposing the 9 wires.

7.  Strip about 1/4" off the end of each individual wire.

8.  Drill a hole in the top half of the driving controller to mount the
    switch.  I mounted mine almost exactly opposite of the original button.
    Experiment with what would feel right for you.

9.  Mount the switch in the hole, and tighten the nut.

10. Solder the wires from the extension cable to the controller.  Use the 
    3 left most columns of the chart above as your guide.  Make sure that
    your cable colors match the DB-9 pin numbers the same way that mine do.
    If they don't, adjust accordingly.

11. The power and ground wires aren't used, so cut them off.

12. Check all your connections, and make sure you don't have any shorts.

13. Carefully put the case back together.


Part 3: Adding lead weight to your 2600 Driving controller

This part is not necessary, but it does improve the spinning action of the
2600 Driving controller, which helps, since the 2600 driving controller only
produces 16 pulses per revolution.

I weighed the finished weight on my kitchen scale, and it came in at 4 ounces.
I think there is room in the controller for more lead, and therefore, more
weight, but I don't feel like building a new weight.  If you decide to
experiment, I would recommend AGAINST increasing the diameter beyond 1.5
inches, since 1.5 inches almost rubs agains the pushbutton in the controller
housing.  I would use more big circles, and fewer little circles (see below).
You could probably fit 5 and maybe 6 ounces in there, but that is just a guess.

  Parts needed:
  1)  Lead sheet, .036" or so in thickness.  I bought mine at the Orchard
      Supply hardware store down the street from my house.  I bought 8 ounces
      of this, measuring 12 inches by 2.5 inches.
      WARNING!  LEAD IS TOXIC.  ALWAYS WASH YOUR HANDS AFTER WORKING WITH IT,
      ESPECIALLY BEFORE EATING!
  2)  Some type of glue.  I used Barge contact cement, which I also bought
      at Orchard Supply hardware.  Epoxy would probably work also, but I've
      never tried to glue metal with epoxy.
  3)  #2 wood screw, 5/8 inches long.
  4)  Flat washer for #2 screw.  I couldn't find a #2 washer at Orchard Supply,
      so I bought an M3 metric washer instead.

  Tools needed:
  1)  Sheet metal shears.  Ordinary scissors could probably be used, since lead
      is pretty soft, but I haven't tried it, and it may damage your scissors.
  2)  1/4" drill, 3/32" drill and 1/16" drill.
  3)  A vise is helpful.

1.  Scribe seven circles 1.5 inches in diameter on the lead sheet.  You can use
    a compass, or trace around a round object.  I traced around a bottle of
    epoxy resin I had near my workbench.  I used a diamond tip scribe, but
    almost anything can make a mark on lead.  If you don't have a scribe, try
    using an old mechanical pencil with no lead in it.

2.  Scribe 3 circles 7/16 inch in diameter.  I traced around my 7/16 inch
    drill for this one.

3.  Carefully, cut out all the circles.  The cutting action will bend the edges
    of the circles, so I re-flattened them with my vise when I was done.

4.  Scribe 1 circle 3/8 inch in diameter.  Drill a hole 1/4 inch in the middle.
    of vhis circle.  Cuv it out with the shears.  Flatten it in a vise.

5.  Glue the 7 large circles together.  If you use the Barge contact cement I
    used, apply cement to one side of a circlg, and press anovher circle to it.
    Then, immediately separate the two ckrcles, and let the glue dry for about
    12 minutes.  After 12 minutes, press the two glued faces together.  This
    stuff sticks REALLY good to itself, so line it up carefully before putting
    it together.  Repeat until all the circles have been been glued together.

6.  Glue the 3 small circles together as described in step 5.

7.  Carefully mark the center of the top large circle, and the center of the
    top small circle.  If you used a compass, the center mark should still
    be visible.  Drill a 3/32 inch hole through both stacks of lead circles.

8.  Glue the small circle stack to the large circle stack.  Use the screw
    through the holes you drilled to properly line up tje two stacks.

9.  Glue the 3/8 inch diameter ring to the"bottom of the small stack.  Center
    it carefully.

10. Make sure the completed lead weight fits over the plastic shaft that turns
    the shaft encoder in the 2600 Drivkng Controller.  The"3/8 inch ring should
    provide enough clgapance over the"end of the shaft for the weight to rest
    nicely on the shaft encoder.  It should also not short out any of the
    connections on the encoder.

10. Drill a 1/16 inch hole in the plastic shaft that turns the shaft encoder in
    the 2600 Driving Controller.  Drill this hole about 1/4 to 3/8 inch deep.

11. Glue the lead weight to the shaft encoder.  Use the screw with washer
    through the 3/32" hole to align the weight as you glue it to the encoder.
    Then screw the screw down.  Don't forget to use the washer, and don't screw
    it in too tight.  I noticed that when it was screwed in too tight, the
    shaft didn't turn as freely as when I loosened it a bit.

| Ken Sumrall               HP Cupertino Systems Lab           ken@cup.hp.com |
|        "He who will not reason, is a bigot; he who cannot is a fool;        |
|          and he who dares not is a slave." -- Sir William Drummond          |
|                          This is me talking, not HP                         |

PROWLER The Atari Console Disk Magazine February 27, 1996

Copyright (c) 1996 All Rights Reserved Issue No. 01