RE: info cpm board for cbm 8032

From: Didier Derny <>
Date: Tue, 24 Nov 2009 20:38:16 +0100
Message-ID: <000301ca6d3d$ab7059a0$02510ce0$@org>

When I was using this board, I never saw the extension
But some people told me it was for a numeric processor

I checked in the chip of this epoch and found the AMD 9511

24 pins
Vcc on pin 2
Vss on pin 1
No idea if pin 3 of am9511 can be tied to gnd

Any idea ? is it compatible with what you can see on the board ?


-----Message d'origine-----
De : [] De la part de Mike Naberezny
Envoyé : lundi 23 novembre 2009 21:38
À :
Objet : Re: info cpm board for cbm 8032

Hi Ruud, wrote:
> The unpopulated socket is meant for a 6502. As the you can see there 
> is no EPROM onboard. The unpopulated 24 pins socket is NOT meant for 
> an ERPOM. Pin 1 and 3 are connected to ground, pin 12 isn't. Pin 2 
> is connected to +5V, pin 24 isn't. I have no idea at all what could 
> fit there.

That is a strange pinout.  I thought that perhaps the socket could also be for 
an Intel or Zilog peripheral chip.  However, I wasn't able to find one that 
matched the pins you listed above.

The board in Dave Dunfield's photo also has the same empty socket.  It could 
be for a proprietary expansion.  This is also a little strange.  I would think 
that any expansion would use headers like the others on the board rather than 
a socket.


Mike Naberezny (

       Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list
Received on 2009-11-25 08:30:25

Archive generated by hypermail 2.2.0.