[Coco] Coco 1 263-3001 just goes to 'ok' prompt when turned on

[Luis Antoniosi (CoCoDemus)]

My coco1 memory chips suffer from extreme persistent memory. Sometimes
I need to power off for up to 7 seconds before turning on otherwise I
get garbage.

I do a test: run a game like tuts tomb. And turn off and on, then I do:

10 PMODE 4:SCREEN 1,1
20 GOTO 20

And I can see the image almost intact sometimes. If I wait 1 second,
then I see some regions fading out, 2 seconds more, and so. I noticed
that I need 7 seconds to have it completely faded.





On Fri, Dec 6, 2013 at 4:50 PM, Arthur Flexser <flexser at fiu.edu> wrote:
> Your CoCo is going to a warm start rather than a cold start.  The most
> likely cause of this is that memory is staying with its previous
> contents despite the lack of refresh while power is off.  Normally,
> the cure would be simply to leave the CoCo off for a longer time
> before powering on again.  You can verify that this is what is going
> on by doing a POKE &H71,0 before powering off, which should cause a
> cold start on the next reset or power on.  If $71 contains a $55 byte
> and $72 contains a zero byte, that tells Basic it should go to a warm
> start rather than a cold one.
>
> Maybe it is something weird with your RAM chips that is causing
> unusual memory persistence?
>
> Art
>
> On Fri, Dec 6, 2013 at 4:29 PM, Jeremy Michea <jmichea at mail.com> wrote:
>> I'm having a problem with this coco 1 i just acquired. When first turned on, there's no extended basic screen, just an OK prompt when turned on. Entering commands just seems to make it freeze or hang.
>>
>> Strangely enough, when I put in a cart, turn it on, and the cart loads fine. Then if I turn it off, remove the cart, and then turn it back on I'll get the Extended Basic Screen. Then turning it off and back on reverts back to just the "ok" at the top of the screen.
>>
>> Sounds like something is bad here but i have no idea what it may be or what to look for (very non-techy) so any help would be appreciated.
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco



-- 
Long live the CoCo