3.2 Jaguar-Controller im Eigenbau

Jaguar-Controller im Eigenbau

Introduction

Here is an ASCII schematic circuit diagram for the joypad controller to the Atari Jaguar (and Falcon and STe). It doesn't discuss the construction but does give an idea of the components you require and how they are connected. You will need a basic knowledge of electronics and soldering.

NOTE: This is for information only.
If you decide to build a joypad using these notes then I cannot be held responsible if what you attach it to blows up. At this current time of writing this design has not been tested in any way. It only follows some backwards engineering of the joypad and hacking with some code on an Atari Falcon.

Copyright

The author distributes this document to the public domain for study, use, and modification. He does request that the comment at the top of each file, identifying the original author be retained.

This document is provided "as is" without express or implied warranty. Andrew Hague disclaims all warranties with regard to this document, including all implied warranties of merchantability and fitness, in no event shall Andrew Hague be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of this document.

You will require for the full implementation

Basic (need for the guts of the device):
20 x diodes (e.g. 1N4148).
6 x 4K7 resistors.
1 x 74LS244 and socket
1 x building board (to mount components on)
1 x 15 pin HD D-type plug and hood.
2m x 15 core wire.
Lots x bits of wire.

Your choice (decide what buttons, joypad, joystick, box arrangement you want):
21 x buttons (SPST - push to make).
A hand sized box or two(!).

Discussion

The pins 1-4 on the joypad's plug are inputs (i.e. connected to addresses that are written to by the computer) and pins 6,10-14 are outputs (i.e. connected to addresses that are read from by the computer). All inputs and outputs are active-low so they float high (+VCC) to represent un-enabled.

The inputs represent allows the computer to ask for a column of buttons to be tested. The outputs enable the computer to decide which row the button was on since it chose a column.

Column  4       3       2       1
--------------------------------------
Row
 6      Pause   ..      ..      ..
10      FireA   FireB   FireC   Option
11      Right   One     Two     Three
12      Left    Four    Five    Six
13      Down    Seven   Eight   Nine
14      Up      Star    Zero    Hash

Inputs

There are 6 buttons wired to pin 4 and 5 buttons each wired to pins 3, 2 and 1. These are shown below. After each button there is a diode to prevent the high level on the un-enabled pins in a column from pulling the input to the IC high again. All pins in a row are merely wired together to act as an active-low AND gate.

[...] == Button, make/break, preferably debounced.
 -K-  == a diode. e.g. 1N4148

   Pins on HD15
        4 ------[Pause]------------ A

        4 ------[Fire A]--K-----|
                                |
        3 ------[Fire B]--K-----|
                                |
        2 ------[Fire C]--K-----|
                                |
        1 ------[Option]--K-----|
                                |
                                --- B

        4 ------[Right]---K-----|
                                |
        3 ------[ one ]---K-----|
                                |
        2 ------[ two ]---K-----|
                                |
        1 ------[three]---K-----|
                                |
                                --- C


        4 ------[Left ]---K-----|
                                |
        3 ------[four ]---K-----|
                                |
        2 ------[five ]---K-----|
                                |
        1 ------[ six ]---K-----|
                                |
                                --- D

        4 ------[Down ]---K-----|
                                |
        3 ------[seven]---K-----|
                                |
        2 ------[eight]---K-----|
                                |
        1 ------[nine ]---K-----|
                                |
                                --- E

        4 ------[ Up  ]---K-----|
                                |
        3 ------[star ]---K-----|
                                |
        2 ------[zero ]---K-----|
                                |
        1 ------[hash ]---K-----|
                                |
                                --- F

Outputs

The IC here is a set of Schmitt triggers which correctly form the output levels.

VCC = pin 7 on controller plug
GND = pin 9 on controller plug
4K7 = a 4.7Kohm resistor.


     A  VCC     B  VCC  C  VCC  D  VCC  E  VCC  F  VCC
        |  |    |  |    |  |    |  |    |  |    |  |
        | 4K7   | 4K7   | 4K7   | 4K7   | 4K7   | 4K7
        +--|    +--|    +--|    +--|    +--|    +--|
        |       |       |       |       |       |
 VCC    |       |       |       |       |       |
 --- |--------------------------------------------------|
  |  |2  4  6  8  11 13                             1|--|
  |--|20                                              10|--+-----|
     |      SN74HC244N                                15|--|
     |                                                17|--|
     | 18  16 14 12 9   7                             19|--|
     |--------------------------------------------------|  GND
             |  |       |       |       |       |
        |       |       |       |       |       |
             |  |       |       |       |       |

Pins    6       10      11      12      13      14 on HD15


-----------------------------------------------------------


ENHANCED JOYSTICK PORT PINOUT (according to Falcon Manual):

   ----------
5    .....   1
10   .....   6
15   .....   11
    -------

DB15 Male (female on machine, male from joystick lead)

Pin     Signal

1       UP0
2       DOWN0
3       LEFT0
4       RIGHT0
5       PAD0Y
6       FIRE0/LIGHT GUN
7       VCC (+5VDC)
8       NC
9       GND
10      FIRE2
11      UP2
12      DOWN2
13      LEFT2
14      RIGHT2
15      PAD0X

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Andrew Hague
188 Tang Hall Lane
YORK
YO1 3RL
ENGLAND
(andrew@minster.york.ac.uk)