[Coco] Update: os9gen on 128k coco3, rs323 pack

[Steven Hirsch]

On Sun, 15 Feb 2009, Steven Hirsch wrote:

> On Sun, 15 Feb 2009, Gene Heskett wrote:
>
>> On Sunday 15 February 2009, Steven Hirsch wrote:
>>> On Sun, 15 Feb 2009, Michael Furman wrote:
>>>> I tried using the rs232 pak ROM and it seems to hang occasionally.
>>> 
>>> There's an obscure problem with interrupt handling that might be behind
>>> the hangs.  I have no personal experience with it, but it's written up in
>>> "Tandy's Little Wonder" (Farna Systems?).  IIRC, interrupts are not
>>> properly shared between the cartridge slot and the GIME with the end
>>> result being that SIO interrupts can be lost.  Again, just speculation
>>> that this is the issue!
>>> 
>> There is about a 100/1 chance that is correct.  The fix is to remove three 
>> of
>> the 4 pullup r's tied to each card socket pin 8, and then jumper all 
>> sockets
>> pin 8's together.  This allows the IRQ to get through to the coco and be
>> serviced regardless of where the slot switch is, or what slot was last
>> selected by the software.
>
> Gene,
>
> I don't think he's using an MPI.  The problem I'm referring to is internal to 
> the computer and has to do with how the cart interrupt is routed to the CPU.

<groan>..  Sorry, getting the threads mixed up.  Mike _is_ apparantly 
using an MPI, but one without the logic update for the CoCo 3 (according 
to an earlier post).

Steve


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