Re: odd cards

[Patrick Schaefer <Patrick.Schaefer@topmail.de>]

>    I have upgraded many computers over the years, and know for a fact some
> Apple's don't like the 2 or 3 chip SIMMs.  I am not saying you can put them in
> one particular machine with a certain kind, but as a general rule stay away
> from them on old machines.  ...

The difference between 2/3 chip and 8/9 chip SIMMs is the number of
refresh cycles required to refresh the whole module. If a 9chip SIMM
module requires 256 cycles (address lines A0..A7), its 3chip counterpart
will require 512 cycles (lines A0..A8).

As a rule of thumb: If your system accepts the next module size, it will
run 3chip SIMMs. That means a computer that accepts 4MB SIMMs will take
3chip 1MB, one that accepts 16MB will run with 4MB chip.


Patrick