Re: Off definition request for design help

From: David Shoemaker <davids_at_wolfenet.com>
Date: Thu Jan 08 1998 - 00:57:39 EST

>You just asked the question wrong, try...
Very good point Zonn :)

<Ahem>

>I am working on a [Cinematronics] multigame rig and in the process of doing
the
>control panel re-routing per game I just don't like my design. As there
are
>many of you here who have very much more EE design knowledge than I, I have
>been wanting to ask forever.
>
>My question is:

I am attempting to route say 8 TTL control lines from point a to point b
with them being re-arraigned as needed for each game. I want to be able to
tie this into a dip switch which picks the "Mode" of the routing.

I can do this with a large amount of digital switches but as I can only do
one mode in no less than 3 of these parts it is a very cumbersome process as
I have say 8 modes to perform.

Graphically I am doing something like this (on 4 modes with 4 lines to save
space)

Mode 1 2 3 4
            a a d d
            b b b c
            c d c b
            d c a a

Where a-d is the source pin designator and its vertical position in the
chart is its destination pin.

I know there must be some way to load the "mode" map into some sort of
controller which would then route signals to the appropriate place.

Ultimate goal would be 16 i/o's with routing. And 8 modes. I am willing to
break this up into as many as 4 parts handling 1/4th the load but I am
really trying to reduce part count. Cost is not nearly as much an issue but
my minimal knowledge of microcontrolers / PLD / GAL / (and the rest of the
alphabet soup that goes around here sometimes :) and there capabilities is.

One idea I had was using 2 large 8bit EPROM's with the inputs from the
control panel being the address select (8 bit + 3 mode select bits) and data
outs being the data out to the game. But this really seems like a large
waste and I am not sure I can reasonably get EPROM's to perform fast enough
for my purpose.

Any additional suggestions would be greatly appreciated,

>BTW: to make things easier it would be nice if this design would also work
with
>a Williams multi-game setup...

:)

Thanks to all.

David
Received on Wed Jan 7 21:58:15 1998

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