Re: 6809 assembly knowledge needed

From: Ethan Dicks <>
Date: Thu, 21 Jan 2010 10:58:45 -0500
Message-ID: <>
On Thu, Jan 21, 2010 at 10:37 AM, Anders Carlsson
<> wrote:
> Ethan Dicks wrote:
>> I forget the minor difference between a 2532 and a 2732,
> Different pinout, I believe.

Yes.  Thanks for the pointer to the pinouts.  The difference (as
relates to reading in a PET) is in pins 18 and 21.

For PET use (i.e., reading from an already programmed chip), the 2532
would treat pin 21 as a no-connect, pin 18 as A11, and pin 20 as the
only chip select.    A 2732 dropped into that socket would want to see
A11 on pin 21 and a chip select on pin 18 (with pin 20 being the
"output enable" pin, in this application, essentially another chip

I haven't tried it, but it should work to stack a couple of 24-pin
machined-pin sockets and swap around signals with those pins to drop a
2732 into a PET.  Mostly, I just save 2532s when I see them - I have
enough for the PETs I own.

> Anyway, I have far more 2516 and 2716 chips than I have '32s. From what I've
> seen, the 2516 and 2716 are functionally identical, just different
> manufacturers.

There is no functional difference I know between the 2516 and 2716.
The 2716 _will_ work as an expansion ROM in a dynamic PET, but you
lose half the space you could stuff another 2K utility into.  My
machine was always loaded w/12K of extra firmware (SuperMON (4K), PET
Rabbit (2K), PAICS BASIC Toolkit (2K) and I'm drawing a blank on the
other 4K now - I haven't used that aspect of the PET in probably 25
years, and I've changed my firmware load a few times as I've fixed
hardware issues).


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Received on 2010-01-21 17:00:05

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