[Coco] Odd behavior

[jeremy michea]

I don't think I've EVER waited 5 or 10 seconds to remove a cart after 
shutting it down. Never heard of this before. I could be damaging my 
coco's by not doing so?

Having grown up from my youth to now switching game cartridges on the 
fly for various computers and game machines, I just assumed that once 
the machine is off, you're safe.

This is good to know.


On 2013-12-17 6:18 PM, Gene Heskett wrote:
> On Tuesday 17 December 2013 18:04:55 Arthur Flexser did opine:
>
>> But such incompatibility wouldn't cause the CoCo 3 to lock up when
>> booted, with nothing on the screen at all, would it, as Bill observed?
>>
>> My impression was that the MPI incompatibility would merely cause
>> certain OS-9 programs to not work correctly.
>>
>> Art
>>
>> On Tue, Dec 17, 2013 at 5:02 PM, Gene Heskett <gheskett at wdtv.com> wrote:
>>> On Tuesday 17 December 2013 16:56:10 Chad H did opine:
>>>> I've never owned or used a MPI.  Were they all CoCo 3 compatible?
>>> Quick answer, No.
>>>
>>> Long answer:  The decoding in them for slot selection responds to the
>>> data being sent to the gime, function as the memory mapper, by
>>> responding to writes to the gime at $FF90-9F.
>>>
>>> The MPI's own control register is at $FF7F, so it can switch slots
>>> when the gimme is written.  There are conversion kits to isolate
>>> that, I believe Mark has then at Cloud9North that you can install if
>>> you solder well, or Mark can fix it.  The kit isn't all that much,
>>> but labor is still labor.
>>>
>>>> Sent from my Transformer Infinity
>>>>
>>>> Bill Gordon <cwgordon at carolina.rr.com> wrote:
>>>>
>>>> I have been fortunate enough to happen upon another Coco3 that I
>>>> could afford, but the ONLY problem with it is that it will NOT work
>>>> with an MPI.
>>>>
>>>>
>>>>
>>>> When the MPI is hooked up, the only display I get is a green
>>>> screen-no garbage, no nothing.
>>>>
>>>>
>>>>
>>>> That's even if the MPI is OFF or ON. Otherwise, the MPI works great
>>>> with my original Coco3.
> Looking back at what you said from Arts perspective, I am inclined to think
> that the coco3 that doesn't work, may have a half blown address bus driver
> in the cpu.  This is something I would confirm by dragging out my dual
> trace scope and checking the logic swings available at the cart socket.
> I'd almost bet on one of them either not pulling down to less than .1
> volts, or up past at least 3 volts. preferably almost 4.
>
> In other words, that coco3 may have been damaged by someone changing game
> carts without shutting it off at least 5-10 seconds before grabbing the
> cart.  A millisecond short between traces is all it would take.  Then, if
> the cpu is damaged its possible to have Mark put a "protector" and a 6309
> in it all in one trip to MN.  Then you would have a super coco3 than when
> running the 6309 built version of nitros9, is nearly twice as fast as the
> NIB version.
>
> Cheers, Gene