28 Nov
2011
28 Nov
'11
6:49 p.m.
On Mon, Nov 28, 2011 at 1:37 PM, Richard <legalize at xmission.com> wrote:
Surely the timing of modern memory chips is fast
enough to meet the
constraints of older systems and one-off PCB manufacturing should
allow you to make the necessary daughter boards for a variety of
machines.
I remember reading somewhere in a memory compatibility guide that the
refresh rate of the memory modules must be within a certain threshold of
the nominal refresh rate, otherwise the cells loose their charge and you
end up with memory corruption. I believe people were trying to use 133MHz
SDRAM DIMMs in a machine that clocked it's memory at 66MHz, and it wouldn't
work.
I'm not well versed in memory design, but you might get it to work with
some buffer circuitry that kept the memory refreshed properly, even if it's
doing nothing for 7 out of 8 cycles.