home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Commodore Free 15
/
Commodore_Free_Issue_15_2008_Commodore_Computer_Club.d64
/
t.cad pad
< prev
next >
Wrap
Text File
|
2023-02-26
|
4KB
|
122 lines
u
Commodore CAD Pad Project
By Rick Youngman
Intro:
Anyone who has ever tried to do any
precise artwork on a C=64 can relate to
this project. To put it simply, is
nearly impossible, to draw a straight
line with a joystick, and making a true
45 degree line, IS impossible. This
project actually was completed 15 years
ago and used not only for a drawing
tool, but also as a game controller.
It is simple, inexpensive, and someone
with minimal soldering skills should be
able to complete it, with a little
effort.
Materials: You will need:
9 - momentary (normally open) switches
1 - 9 pin DB9 plug (or a chopped off
cord from an old joystick)
Some wire/solder & stuff like that.
8 - Diodes *
Silicon switching diodes. Radio Shack
#276-1620 (pack of 50 for $ 2.98)
(also known as signal diodes)
1 - Controller case
What kind of switches you use, and how
you set this project up in a case is up
to you.
How it works:
The position of the cursor at the
joystick port is read by simply
grounding pins 1-4 and pin 6 (FIRE
BUTTON). I.e. grounding pin 1 makes
the cursor (or sprite) move UP, and
grounding pin 4 makes it move to the
RIGHT. That is great, in theory, but
not precise in practice, because one
slip of your hand will trigger another
direction, and all you have is a
crooked line. Trying to hold a joystick
handle to draw a 45 degree line is even
worse. So the solution is to
mechanically close the contacts by
push-buttons, allowing precise control
of the cursors movement. This project
goes one step further, by allowing you
to use ONE button to push TWO!! This is
explained better by considering this.
If you wanted to move the cursor at 45
degrees to the right, you would have to
hold both the RIGHT, and UP button at
the same time. That works, ONLY I MEAN
ONLY --- you can push both buttons
EXACTLY at the same time! That's
impossible! Not any longer.. Because
we are going to add that button!
Look at the picture online and you will
understand.
The concept is so stupidly simple, I
won't go into the all the nitty gritty
here. For this explanation, we will
only look at making a 45 degree angle
to the upper right area of the picture.
Because of the diodes inline on switch
# 3, they prevent feedback between SW 1
and SW 2, so pressing either of those
switches allows them to act normally,
BUT, by pressing SW 3, the ground is
now latched to the output of BOTH of
those switches AT THE SAME TIME,
resulting in a perfect 45 degree line!
Some Suggestions:
How you use this project, and construct
it is entirely up to you. It is simple
enough to be able to just mount some
cheap switches in a box and wire the
diodes point-to-point, or you can make
a PC board, if you have the skills.
If you want to use this project as a
game controller (it works very well for
that too) keep in mind what kind of
switches you will use, and how much
abuse they will handle.
How you locate the switches is up to
you. Or you could even setup the
switches like a Playstation pad too.
Full Layout
Closing Note:
I have started to make a template for
you that want to etch your own PC
board, but any help there would be
welcome, as my time is limited (and the
software I use for making etch patterns
really sux, and takes boo-koo time !)In
the mean time, here is a simple
hardware hack, that will be very
useful, and can supply a missing link,
to something that was never produced.
Rick Youngman
http://users.commspeed.net/wlbbs/
CAD-PAD.html
COMMODORE FREE
Would like to thank Rick for permission
to reprint this project in the magazine