The Mac Plus, needs special attention when installing ram. Simply remove all the screws from the back of the Plus's shell. You must use a star shaped screwdriver, such as a torxs wrench. Once you have the cover off locate the mother board containing the Ram. This is easy to find. There are 4 simm slots, if you have a 1 meg configuration, there will be 4, 256k simms in the slots. Remove these and install your 4, 1 meg simms in there place.
Now here is how you get your Plus to recognize the new Ram. Next to the simm slots, there are two numbers on the board, (R8) and (R9). Under R8 it should say, "256kbit. And under the R9 one, it should say One row.
Take a wire cutter and snip off the resistor at (R8) the 256k one. Easy, now your Plus will be able to address the additional Ram. Replace the cover and your on your way....
Future System Software Support For The Plus?
With the release of System 7.5.5 Update, Apple is delivering its final system software release for the Macintosh Plus, SE, Classic, Portable, PowerBook 100, SE FDHD, SE/30, LC, II, IIx, and IIcx. These computers were not designed to support 32-bit memory addressing. Future Mac OS releases will require 32-bit memory addressing, which is supported by all other Macintosh models.
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