Re: Asteroids state machine??

Well, I don't have all my Asteroid notes at home, but...pin 23 is A13 and I
would expect it to be pulsing, along with pin 34 (R/W) . Pin 40 is the
RESET pin, and it should be high with no pulses. Remember that the IRQ sets
the rate of speed on the game, so see if this sub-board interferes with the
IRQ ICs, and return them to normal (factory wiring) if it does - but make
notes on the connections and changes so you can try it out later once the
board is running normally.

John :-#)#

At 06:35 PM 23/03/2003 -0500, MKDUD@aol.com wrote:

>
>Hello,
> I'm still trying to fix the Asteroids board with the "sonic"
> daughtercard on it.
> I'm sure it is a speedmod, but I wasn't sure exactly how it worked -
> the IC's on the card have been scratched so you can't read them. I'm
> guessing the 8 dip has to be a 555 timer, but I'm not sure about the other IC.
> Any ideas about how to debug the state machine? When I lift pin 1 of
> the LS42 @ L6, the watchdog stops, and the game plays blind & passes self
> test with no errors. Obviously, there is no picture with /DMAGO disconnected.
> With the machine in test mode, /DMAGO connected and WD disabled, I'm
> getting what look like reset (or WD) pulses on pin 23 of the 6502A (A13).
> Pin 34 (R//W) of the 6502A is doing the same thing with the WD disabled.
> Obviously, this is is screwing up lots of stuff associated with the
> address decoder. I have already replaced L6 (LS42), B2 (LS244), and all
> rams. I don't know what else I should be checking. Any help would be
> appreciated.
>
>Thanks,
>MK

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Received on Sun Mar 23 19:42:33 2003