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

[Gene Heskett]

On Sunday 15 February 2009, Michael Furman wrote:
>On Feb 15, 2009, at 11:42 AM, 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.
>
>Gene and Steven -
>
>Can you cite some more exact references to articles on these mods,
>like to files on maltedmedia or rainbow issues etc.?  I am using a MPI
>btw... Otherwise I couldn't have the  FDD and serial ports connected
>at the same time.  I'll also do some searching in GMANE to see if this
>has been discussed before (I'm certain it has been, both topics seem
>familiar)
>
I have probably given much more explicit instructions at some point in the 
past that s/b in the list archives.

There are in fact at least half a dozen variations of this, some of which are 
even on rtsi, but IMO they do not address the real problem in a no wires into 
the coco required manner.  The real problem is that Tandy, in their infinite 
wisdom, thought the mpi was gonna be full of auto starting game packs.  
Around my place, that might have happened once in 20 some years, and I have a 
grocery sack full of games.  I even put a list up here to see if anybody 
wanted any of them 2 or 3 years ago, but there were no nibbles.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
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