use of +12 and -5 on commodore 8032

From: Didier Derny <>
Date: Wed, 7 Sep 2016 13:29:22 +0200
Message-ID: <>

any idea if  +12v and -5v are used for anything else than  the 4116 ?

the idea:
all original  regulator removed (easy to put back in place)   (+5 +12 -5 
disconnected from the original power supply)
+5v regulated directly injected on the motherboard
+12V connected to +5v regulated  (strap between the 2 regulator output )
4164 installed in place of 4116

the 4164 would get 5v by the 12v track (now 5v with the modification)
pin 1  -5v  not connected (-5v removed)
pin 8  +5v (+5v coming by 12v track)
pin 9  A7  (forced to 5v by 5v track)

seems similar on some modification made on atari

may any potential side effect on some other part of the system...
I dont see any real use of the +12v and -5v except for the 4116
but I might have missed something

for the +9v unregulated I never found any used except for the tape
but I'll probably never use a commodore tape...

the main idea is to avoid any permanent modification on the board...

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Received on 2016-09-07 12:00:04

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