Re: 6522 VIA inputs

From: Mike Naberezny <>
Date: Fri, 21 Apr 2017 10:12:49 -0700
Message-ID: <>
On 4/21/17 9:10 AM, Gerrit Heitsch wrote:
> Take a look at the MOS datasheet for the 6522 (If you can't find it, I can 
> mail it to you), it has schematics for the port drivers for port A and port B, 
> they differ, but both ports have a permanent pullup in form of a MOS 
> transistor for each bit.

The MOS 6522 datasheet can be downloaded from here:

The port drivers are on page 3 of the PDF.  The Rockwell and Synertek 6522 
datasheets are also on


Mike Naberezny (

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Received on 2017-04-21 18:00:02

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