[Techtoolslist] Simpler way to upgrade Williams video to 4164/4264

[John Robertson]

I found what is a pretty simple way to upgrade these motherboards 
(Defender/Stargate/Joust/Robotron/Etc.), simply remove the 12V choke 
(bottom most coil) and the -5V choke, which is the top one of the four 
choke coils.

Then run a jumper from the +5 choke output to the old 12V choke output.

No cable changers (which can get lost/misplaced/buggered) needed - if 
you can build a cable changer you can easily modify the board.

This removes the -5 and the +12 from the RAM and converts the original 
+12 to 5VDC which the 6164/6264 requires. Note that pin #9 which is A7 
on the 6164/6264, when plugged into the 6116 socket has the 5V Vcc 
connection, which is irrelevant as A7 can be pulled high forever.

John :-#)#
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