Re: Millipede to JAMMA? Anyone?

-----Original Message-----
From: Mark E Davidson <mark@basementarcade.com>
To: rasterlist@vectorlist.org
Date: Wed, 23 Nov 2005 09:59:22 -0500
Subject: RASTER: Millipede to JAMMA? Anyone?

>
> Wondering if anyone here has ever successfully made a Millipede to Jamma
> adapter?

i did it with missile-command.

you need an amplifier - obviously.
then you need to build a small oscilator using a 555 timer.
now it get's a bit techy.

to use the trackball inputs you need to understand the principle.
there are 2 lines per axis.
1 for pulses, and one that either precedes or foillows the pulse to indicate direction.

luckily the software isnt too fussy about the second signal.

connect the down input to the y-quadrature input through a diode.
connect the up and down through some diodes to a gate or transister or something that will connect the output from the oscilator to the other y input.

what your after is for stick-up to connect the pulses only, and stick down to connect the pulses and pull the other line low.

if it goes in the wrong direction then swap the up/down connections.

repeat the switching circuit for the x-axis and feed it from the same oscilator.

the speed of the oscilator will determin the speed of movement on the screen.

missile-command is surprisingly playable with a joystick! :-)

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Received on Wed Nov 23 10:16:32 2005