Re: cbm 8032 motherboard + atx power supply

From: Ethan Dicks <>
Date: Fri, 19 Aug 2016 10:52:18 -0400
Message-ID: <>
On Fri, Aug 19, 2016 at 10:37 AM, David Wood <> wrote:
> Is anyone familiar with what -5v is used for on PETs?

Negative bias voltage for the 4116 DRAMs, a few dozen mA, IIRC.

(if you have socketed DRAM and..) if you did the pinballer hack of
modding 4164s for use in 4116 sockets (lift out the -5V pin from the
socket, and run a jumper over the top of the chip to the high address
bit are the steps from memory), you might not require -5V at all.  The
schematics are out on and shouldn't take long to verify
that's the only use.


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Received on 2016-08-19 15:00:03

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