Williams Switchers

TRK

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Are the Williams Switchers available at different places with power supply killer or what!

Im just overly excited that for 10.00 more than a complete PS rebuild kit (super shotgun) you can just convert it in 10 minutes flat and be done with them.

Yeah I am easily impressed!

I have always t-shot the junk or rebuilt it out of pride.. what a waste of #amn time that was!
 
Yeah - it seems great. Until you run into one of those problems Wms games sometimes have with switchers installed. Do some research on it before you do it.

I just rebuild the original and it works fine...
 
Yeah I had heard about audio issues I thought? I havent run into that in Robotron or Joust at least not yet.

Yeah - it seems great. Until you run into one of those problems Wms games sometimes have with switchers installed. Do some research on it before you do it.

I just rebuild the original and it works fine...
 
The sound is somewhat quieter because most switchers don't have -12V so they substitute the -5V. That is not the major issue. The original linear power supplies were designed to mitigate a bug in the 6809 processors. When the 6809 is shutdown it will write random values to the memory space, including the CMOS memory. The original PS boards have a large capacitor on the +5V which will power the CPU for a few milliseconds while the +12V drops. There is a CMOS memory protect circuit that monitors the +12V and when it drops, the memory protect kicks in.

That doesn't exist in the switcher, so periodically when shutting off the power the CMOS will get trashed. This could be the high score table, the bookkeeping or the settings.

Some board sets seem to be more sensitve to this power down trashing than others. Defenders seem to be very sensitive to it, Robotrons a little less and Joust seem to be the least affected.

ken
 
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