Re: Asteroids daughtercad ????

I'd be interested.. always wondered why some boards looked unchanged, yet
played at different speeds....
> There were some interesting kits sold back in the early 80's that allowed
> one to speed up the game. I recall hearing of one that changed the speed
> automatically. Check if the IRQ control IC has any cut pins, that is where
> they fit in the speed up normally.
>
> We used to do it with the two of the unused 4 Dip Switch switches and tied
> them to the 74193 (? - I have to check that) IRQ clock divider pins that
> were tied to ground, and with a couple of pull-up resistors one could get
> quite a nice speed up of the game. I have a picture I think of the last
> board I did this to if anyone is interested...
>
> John :-#)#
>
> At 04:18 PM 20/03/2003 -0500, MKDUD@aol.com wrote:
>
>
> >I'm trying to repair an Asteroids board with VSM troubles. This board has
> >what I'm guessing to be a "speed up" daughtercard mounted to the board.
> >See Pics:
> >
> ><http://members.aol.com:/mkdud/ast/astdc1.jpg>http://members.aol.com:/mkdud/ast
> /astdc1.jpg
> >
> >http://members.aol.com:/mkdud/ast/astdc2.jpg
> ><http://members.aol.com:/mkdud/ast/astdc3.jpg>http://members.aol.com:/mkdud/ast
> /astdc3.jpg
> >
> >Does anybody know anything about these daughtercards? This one is etched
> >"Sonic 1B-2001-022" on the back. It has one modwire going to the cathode
> >side of CR1 (1N914) near the reset button, another going to pin "C" of the
> >edge connector, and power wires +5 and Gnd.
> >Why would this wire go to pin "C" of the edge connector? For a switch in
> >the cabinet, perhaps?
> >I was wondering how these cards worked (overclocking, I guess), and if it
> >could screw up the VSM. Also, does anybody have a VSM debug proceedure for
> >Asteroids?
> >
> >Thanks,
> >Michael Kelley
>
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Received on Thu Mar 20 14:55:08 2003