Macintosh SE 2/40 Upgrade: SIMM Requirements



To upgrade a Macintosh SE 2/40, do the two additional 1MB SIMMs need to be the
same speed as the original 2MB SIMMs?

If so, is there any way to determine the speed of the installed RAM without
opening the Macintosh SE case?

The Macintosh SE 2/40 requires SIMMs that are 150ns or faster. If the SIMMs
already in the Macintosh SE are 120ns, you can add two more that are 150ns.
The important thing is that the SIMMs in each group (group A is SIMM slot 1
and 2; group B is SIMM slot 3 and 4) must be the same speed.

The only way to tell the speed of the RAM installed is to look at the RAM chips
themselves. Typically the 120ns RAM chips will have a "12" printed on them and
the 150ns RAM chips will have a "15".


Published Date: Feb 18, 2012