[Coco] Compatible RS MPIs to Coco 3
mvmiller12 at hotmail.com
Sat Dec 26 12:18:27 EST 2020
I also wanted to add that I got a 3024 MPI late last year, and I was still able to readily get the necessary chip to upgrade it. I believe I got the chip mailed to me from Cloud9, but that may be my hazy memory... afterall I AM old enough to have had a new Coco as a young child 😊.
From: Coco <coco-bounces at maltedmedia.com> On Behalf Of Ed Snider
Sent: Saturday, December 26, 2020 11:58 AM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] Compatible RS MPIs to Coco 3
It's the 26-3024 that can be easily upgraded with the chip swap. The chip in question is a PAL16V8 which can be replaced with a compatible chip (PAL or GAL) containing the upgraded logic.
The new logic basically keeps the MPI from responding to the addresses added in the GIME when the CC3 was introduced (not an issue on CC1/2) to avoid bus conflicts.
> On Dec 26, 2020, at 10:05 AM, Michael Kline via Coco <coco at maltedmedia.com> wrote:
> Hi Jeff,
> Thanks for the info. What chip do you swap out and are they available? Probably EPROM now-adays.
> On 26/12/2020 09:46, Jeff Teunissen wrote:
>> No _unmodified_ Multi-Pak Interface is compatible with the CoCo 3. I
>> believe that there was a time when Tandy took all of the 26-3124 "new"
>> MPIs they had in their warehouse and upgraded them to work with the
>> CoCo3, resulting in 26-3124A.
>> So I guess there's one model of MPI that's CoCo3-compatible out of
>> the box, the pretty-rare 26-3124A. All other models are incompatible
>> unless modified. The old 26-3024 MPIs are pretty easy to upgrade, you
>> replace one chip with another. The upgrade to the newer 26-3124
>> version is more involved, and probably shouldn't be done unless
>> you're pretty confident with a soldering iron.
>> On Sat, Dec 26, 2020 at 10:18 AM Michael Kline via Coco
>> <coco at maltedmedia.com> wrote:
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