10 Apr
2007
10 Apr
'07
5:12 p.m.
On 10 Apr 2007 at 22:57, Tony Duell wrote:
Have you tried just a new chip in place of a
piggybacked module? I wonder
if the new chips are actually 128K bits -- that is, they're really the 2
old chips of the pigyback on one die, in one package. If you piggybacked
a new chip onto half an old pair, you'd end up with 2 chips 'in parallel'
for half of the memory space, that might not matter (if you never read an
un-wirtten-to location, there will be no contention becasue the same
value will have been written to both chips)
This reminds me of the early revs of the PC AT, which used (IIRC)
stacked 64K DRAMs (the bottom used a different select than the top
one, so that they could be just soldered pin-to-pin) to get a 128K
module.
Cheers,
Chuck