[Coco] Compatible RS MPIs to Coco 3
zippster278 at gmail.com
Sat Dec 26 11:58:17 EST 2020
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
> 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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