[Coco] the amazing memory persistance

[John Kowalski]

Luis Antoniosi (CoCoDemus) wrote:
>in case you don't believe me:
>http://www.youtube.com/watch?v=vno_T2-FP2E
>what can i do to solve this ? Put a resistors some place?

That's pretty insane.  I would suspect that it's the capacitors
internal to the DRAM itself that are holding their charges so long
that it's acting like battery backed-up memory.

I've had a CoCo that retained it's memory for a couple of seconds, but
this is just astounding.

The chips are MB81464?? You could try maybe placing a 1 KOhm resistor
across pins 9 and 18 of (just) one of the memory chips and see if that
changes anything, but that might not help if the DRAM's internal
capacitors are isolated from the power input.   If it doesn't, maybe
try the resistor across pins 2 and 18 to see the charge could be
drained from one of the data lines when it's powered off.  If this
works but only slightly, you may try adding a resistor to each chip -
and then if still only slightly, one for each data line (between pins
2&18, 3&18, 15&18, 17&18).

-- 
John Kowalski / Sock Master
http://users.aei.ca/twilight/sock