Misc. Joystick Notes
From: JTKIRK@urp.edu.pe
Date: 02/01/96-05:09:28 AM Z
From: JTKIRK@urp.edu.pe
Subject: Misc. Joystick Notes
Date: Thu Feb 1 05:09:28 1996
Joystick miscellany
-------------------
1- Analog joysticks
-------------------
Have you ever considered the fact that an IBM-PC-type analog joystick
consists of two potentiometers (one each for the x- and y-axis) and two
pushbuttons, just like a set of ATARI (or Commodore) paddles? Have you
ever thought of connecting such a proportional joystick to your ATARI or
Commodore computer in order to use it with your programs? Well, here's
how to build a 15-pin analog joystick port from 2 9-pin ATARI ports. You
will need a 15-pin and 2 9-pin female connectors and a 15-wire cable.
Internally, the analog joysticks are basically like this:
pb1A
|
O
| Y1
pb1B -O--+ | U
| |
GND Z
/->Z Ry Rx=Ry=200-250 K
| Z
/----\ | |
v | \--+ D
X1 ----NNNNN--+----+----- +5V
L Rx R
The pin assignmet in the 15-pin IBM-connector is the following:
pin ________________________
# function \8 7 6 5 4 3 2 1/
------------ \15_14_13_12_11_10__9/
1 +5V
2 pb1A
3 X1
4 GND
6 Y1
7 pb1B
10 pb2A
11 X2
13 Y2
14 pb2B
Similarly, the pin assignment for the DB9 connectors (in the case of
paddles) is the following:
pin ___________
# function \5 4 3 2 1/
------------ \9_8_7_6/
3 L button
4 R button
5 R paddle
7 +5V
8 GND
9 L paddle
Well, let's begin with the connections for 1 analog joystick. Take the
cable and use it to connect the following pins on the 15-pin connector
to the corresponding pins on one 9-pin connector:
15-pin 9-pin
-------------
1 -> 7
2 -> 3
3 -> 9
4 -> 8
6 -> 5
7 -> 4
Now, you can try connecting the 9-pin female to joystick port 1 on your
computer and the analog joystick into the 15-pin female connector. Then,
write and run a subroutine like this and try moving the joystick and
pressing the buttons:
0 PRINT PADDLE(0), PADDLE(1), PTRIG(0), PTRIG(1):GOTO 0
You could also load any program which uses a touch tablet and test the
joystick instead (e.g, ATARI ARTIST).
If you have a dual analog joystick ('dual' in the same way that paddles
are connected by pairs to a single port), then you can now make the
following additional connections from the 15-pin female to the second
9-pin female:
15-pin 9-pin
-------------
10 -> 3
11 -> 9
13 -> 5
14 -> 4
Now connect the second 9-pin female to joystick port 2 on your computer;
the second analog joystick should be readable through PADDLE(2), PADDLE(
3), PTRIG(2) and PTRIG(3).
2- Portable autofire
--------------------
This is a solution for those joysticks which don't have a +5V line (red
wire typically, connected to pin 7). You will need a 9-pin female and a
9-pin male connector, an LM 555 timer IC, two resistors (R1=R2=10 K),
two capacitors (C=100 nF, C1=0,42 nF), a two-position switch and some
wire. Since you will need also an appropiate casing, I would recommend
you to use a 9-pin null modem adapter (e.g., Radio Shack #26-264), which
will provide you already with the casing, wiring and DB9 connectors.
First, build the following autofire circuit in the smallest possible
area (less than 0,5"x0,5"):
+5V
|
/----------+
| |
Z /--+
R1 Z .__|__|__.
| | 8 4 |
+----7 |
| | 3----- fire
Z | LM 555 |
R2 Z /-6 5----\
| | | | |
+--+-2 | = C1
| |___1____| |
| | |
\---||---+---------/
C |
GND
If you are using the null modem adapter, skip this paragraph and continue
with the next. If you aren't and are building the adapter with separate
parts, then just connect each pin from the 9-pin female to the same pin
on the male connector. Now you've just built what the adapter looks like
on the inside.
Now, if you are using the null modem adapter: just open the casing and
accomodate the circuit inside. Make sure that all pins on the male are
connected to the same pin # on the female (i.e., pin #1 to pin #1, pin
#2 to pin #2, etc.) and not cross-connected.
Now for both: Connect the +5V line to pin #7 (either on the male or the
female connector, it's the same). Similarly, connect the GND line to
pin #8. Cut the wire from pin #6 just in the middle. Now, proceed to
make the following connections on the switch:
/
A / B
o o o
to | | | to
male --/ | \-- fire
|
to female
Now, make the appropiate holes in the casing for the switch. Fix the
switch in place and close the casing. Now the portable autofire is
ready for use.
Just connect the portable autofire between the joystick port on the
computer and the joystick's plug. With the switch in the A position,
you will simply bypass the autofire circuit (autofire disconnected);
when it is in the B position, the autofire is connected and the
joystick's fire button is disabled. The advantage of this design is
that you can connect the portable autofire to any joystick you want,
without having to make any permanent modification to it.
3- Tank-style levers
--------------------
Surely you remember BATTLEZONE (tm), don't you? I loved playing that
game on the arcades, since it was one of the first games to offer you
3-D graphics and a first-person viewpoint. Then ATARI released it
for its 2600 VCS (after many years), with some of the best graphics
I've seen on the 2600 VCS. And then came the version for ATARI 8-bit
computers... the only one I haven't seen, because somebody stole the
last cartridge from the computer fair back in 1989; I assume the
controls were like the 2600 VCS version:
forward
^
turn left | turn right
rotate \ | /
counterclockwise <----*----> rotate clockwise
/ | \
reverse left | reverse right
v
back
The arcade version had real tank-like controls instead:
left right
tread tread
forward ^ ^ forward
| |
motionless + + motionless
| |
back v v back
The combined motion of both treads gave the same 8 different possible
movements for the tank.
Well, if you (like me) aren't happy with using just the joystick and
want to have a more 'realistic' feeling, here's how to build your
tank levers, including the necessary circuitry to provide the
respective joystick signals for each combination.
Let's compare the switch values for the 9 joystick positions and the
9 tank-lever positions:
joystick tank levers
U X Y
SWITCHES L-+-R | |
D Z W
movement RLDU XYZW
---------------------------------------------
motionless 1111 1111
forward 1110 0011
back 1101 1100
counterclockwise 1011 1001
clockwise 0111 0110
turn right 0110 0111
turn left 1010 1011
reverse right 0101 1101
reverse left 1001 1110
The functions which map (X,Y,Z,W) to (R,L,D,U) are:
_ ___
R = Y + X.Z + Z+W _
_ ___ = NOT
L = X + Y.W + Z+W
___ . = AND
D = X.Y + Z.W
___ + = OR
U = X.Y + Z.W
You will need:
- 1 74LS04 IC (6xNOT) (IC1)
- 1 74LS08 IC (4xAND-2) (IC2)
- 2 74LS32 ICs (4xOR-2) (IC3 and IC4)
- 4 14-pin IC sockets (optional)
- 1 2"x3" IC PCBoard (like Radio Shack #276-150A)
- lots of jumper wires
- soldering iron and solder wire
- 1 9-wire cable (as long as you like)
- 1 joystick connector (9-pin, female)
- 4 pushbuttons for the lever switches (X, Y, Z and W)
- as much pushbuttons as you want for firebuttons
- 1 board for mounting the switches
- 2 self-centering levers (inverted T form)
- 1 casing for the whole
Connections:
------------
First, solder all wires of the cable to the 9 pins of the joystick
connector. The free ends of the wires will be referred to as joyN,
where N=1-9 is the corresponding pin number at the connector.
___________
\5 4 3 2 1/
\9_8_7_6/
Mount all 4 lever switches in their board, properly spaced. Remember
that the levers are supposed to press them once in place.
X -O O- Y
| |
+-----+--- GND
| |
Z -O O- W
Solder the 4 sockets (or the ICs, directly, if you're cheap) in place
in the PCBoard. Pin # of ICx will be referred to as ICx-#, where x=1-4
and #=1-14.
_______________________________
|() ....................... ()|
| .:::::::::::::::::::::::. |
| ::|o_IC2__|:::|o_IC3__|:: |
| ::::::::::::::::::::::::: |
| ::::::::::::::::::::::::: |
| ::::::::::::::::::::::::: |
| ::::::::::::::::::::::::: |
| ::|o_IC1__|:::|o_IC4__|:: |
| ::::::::::::::::::::::: |
|()_________________________()|
Now use the jumper wires to make the following connections:
+5V: joy7, IC1-14, IC2-14, IC3-14, IC4-14
GND: joy8, IC1-7, IC2-7, IC3-7, IC4-7, ground of all pushbuttons
R: joy4, IC4-6
L: joy3, IC4-8
D: joy2, IC3-3
U: joy1, IC3-6
FIRE: joy6, trigger of (all) firebutton(s)
X: switch X, IC1-11, IC2-2, IC2-4
Y: switch Y, IC1-9, IC2-5, IC2-10
Z: switch Z, IC2-1, IC2-12, IC3-12
W: switch W, IC2-9, IC2-13, IC3-13
IC1-1, IC2-6, IC3-4
IC1-2, IC3-2
IC1-3, IC2-11, IC3-1
IC1-4, IC3-5
IC1-8, IC4-1
IC1-10, IC4-13
IC1-12, IC4-5, IC4-9
IC1-13, IC3-11
IC2-3, IC4-2
IC2-8, IC4-12
IC4-3, IC4-4
IC4-10, IC4-11
If you're using sockets, then now you can place the ICs on them.
You can include an autofire switch in the design, if you want. You could
also have the two pots (joy5 and joy9) being used for anything you can
imagine.
Make sure the levers will press the pushbuttons when pressed. You will
have to assemble the whole thing inside the casing, making it fit.
Now you're ready to blast those @&%# enemy Automatons!
Marco Antonio Checa Funcke
Botoneros 270
Lima 33
Peru
reachable at jtkirk@urp.edu.pe
-----------------------------------------
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