| I solved this problem on the Atari by means of a "joystick extension
cable" from Radio Shack. ($4.95 - cheapest matched pair of 9-pin DIN
connectors I've ever seen.) (On the Atari 1040, the mouse/joystick
connectors are on the BOTTOM, which makes them particularly difficult to
access.) I then do all my switching at the joystick end of the
extension cable, which saves wear and tear on the Atari connector, not
to mention my fingertips. If you would like to use a REAL SWITCH, you
need to go to a store that carries large switches, such as Active
Electronics in Westboro, or "You Do It Electronics" somewhere south of
I-90 on Rt 128. You could then hack up a pair of joystick extension
cables and connect them to the switch inside the little box. (Leaves an
extra 9-pin male D-sub hanging around.)
Note that you only need an 8-pole switch, since there is nothing wrong
with connecting the GROUND connection to everything at once. In the
case of the Atari, you would only need a 4-pole switch, since you only
need to switch the four quadrature signals from the mouse. It's
possible the same is true for the Amiga as well. It is perfectly safe
to connect the switches together in parallel, it simply means that you
can press switches on either device, regardless of which is currently
"enabled".
If you can't get, or can't affort, a 8-pole switch, or can't use a
4-pole in your situation, you can make a circuit that contains a single
pole switch and a multiplexer. A multiplexer is a an intergrated
circuit that has (typically) eight inputs and four outputs, and a
control input that determines which half of the eight inputs appear on
the outputs. You can then switch the one control input with a very
simple switch, and the rest are switched inside the circuit. Depending
on what's inside the joystick, this may require pull-up resisitors on
the inputs. If you are REALLY clever, you can use a parallel output bit
somewhere, and do the switching in software in the computer.
|
| Re: .1
Thanks! That is the kind of information I was looking for, particularly the
names of places that might have that kind of switch. Also a good idea about the
ground, since I presume an 8 pole switch is easier to find than a 9 pole.
I am a little leary of just using a Y connector. Might be ok for mouse vs
joystick. (Tho it can really piss off someone in the midst of a game.) I was
thinking of having a dongle in one of them. I am not sure how software senses
dongles, but having it in a Y with a joystick sounds like it might be trouble.
I might look into switching only some of the 8 lines if an 8 pole switch is
expensive, but it seems like it would be easier in the long run to do it right
the first time.
Regarding the multiplexer: sounds like a nicer solution, but wiring up an 8
pole switch is about at the limit of my electronic ability, so what you are
proposing isn't a possibility for me. However, if someone wants to go into
business manufacturing gameport A/B switches this way I might be willing to buy
one.
Paul
|