[Coco] multipak question

[Little John]

> It has been years since I followed up closely on this subject in CoCo
> magazines: what is the impact on a regular CoCo 1 & 2 after the MPI is
> upgraded for proper CoCo 3 operation? any software/hardware packages that
> may balk at the upgrade?
=====================
The upgrade limits the memory area of the MPI data buffer to $FF40-$FF7F. On 
an UN-upgraded MPI, the data buffer will respond to addresses all the way up 
to $FFBF. Yes there are some CoCo 2 devices that wont work after the 
upgrade, notably the first SuperVoioce which is mapped at $FF8x - later 
versions changed the mapping making it compatible after the upgrade. There 
were a few other pieces of hardware - I think ColorWare's Voice Pak also 
doesn't work after the upgrade.

----- Original Message ----- 
From: "Rogelio Perea" <os9dude at gmail.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Monday, October 25, 2010 7:13 PM
Subject: Re: [Coco] multipak question


> On Sun, Oct 24, 2010 at 8:57 PM, Little John <sales at gimechip.com> wrote:
>
> Jeremy,
>> you can order an upgrade chip ready to go right here:
>> http://www.frontiernet.net/~mmarlette/Cloud-9/Hardware/MPI%20PAL.html<http://www.frontiernet.net/%7Emmarlette/Cloud-9/Hardware/MPI%20PAL.html>
>> Mark includes complete installation instructions - but you basically just
>> swap the chip. Of course, Mark also provides the following info:
>> Does My Multi-Pak Need This Upgrade?
>>
>> Here's a simple test that will determine if your Mulit-Pak has already 
>> been
>> upgraded to work with a CoCo 3. From BASIC's OK prompt, type PRINT
>> PEEK(&HFF90) and press ENTER. If 126 is returned then the Multi-Pak has 
>> been
>> upgraded. If it returns 255 then it has NOT been upgraded.
>>
>
> Tried this test on my CoCo 1 setup which has a 3024 MPI, am I ok to assume
> the PEEK into &HFF90 returns a trustworthy decimal 255 on the noted
> hardware? or is this test CoCo 3 specific?
>
> I remember trying out that same MPI on my CoCo 3 a while ago, never had 
> any
> problems even with OS9LII - could be I just got lucky at that time.
>
> It has been years since I followed up closely on this subject in CoCo
> magazines: what is the impact on a regular CoCo 1 & 2 after the MPI is
> upgraded for proper CoCo 3 operation? any software/hardware packages that
> may balk at the upgrade?
>
>
> -- RP
>
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