Task: Upgrade a Macintosh Classic II Computer to 10MB of RAM
Needed: Two 4MB RAM Boards, Mac Classic II, Long T15 Torx Screwdriver
Time: 15-30 minutes
Introduction
I acquired a lovely Macintosh Classic II several years ago from a local contact. The first thing I did was replace the leaking capacitors that are common to all Macs of the 1990s. I have previously described how to do this.
The Classic II came out in 1991 and was sold through 1993. It is a cost reduced version of the popular SE/30. It also has a Motorola 68030 processor, but Apple decided to downgrade the data bus to 16-bits. This means the system can only address a maximum of 10MB of RAM. The Classic II comes with 2MB of onboard memory. Mine came with an additional 2MB (two 1MB SIMMs) for 4MB total. This is on the low end and means this machine could not run some software. Fortunately, new 4MB SIMMs are readily available for this model and the install is quick and easy.
Instructions
First, purchase two 4MB SIMMs cards that are compatible with the Mac Classic II. I got two on mine from Keystron on eBay for $15. Compatibly includes 30 pins, non-parity, and faster than 100 ns.
Second, use a long T15 Torx screwdriver to remove the four case screws on the back. There are two recessed deep under the handle on top and two more on the bottom.
Third, remove the case upward with the monitor screen facing down on your surface. The case can be a little tight to get off. Do not use a screwdriver to wedge it or you will break the plastic. The key is to apply firm upward pressure on both sides.
Fourth, remove the square attachment on the neck of the CRT. Pull it gently straight off and tuck it off to the side. This is important because the next step requires pulling some connector up and if your hand slips it could hit the neck and break it requiring the entire CRT to be replaced.
Fifth, carefully and gently and slowly reach down to the circuit board at the bottom of the case and remove several connectors. My Classic II had three connectors to remove. Do this slowly so your hand does not jerk upward risking breaking the CRT neck (not good!).
Sixth, slide the circuit board out toward the back of the computer exposing the two RAM SIMMs (see below).
Seventh, carefully and release the metal clips on the side of each 1MB SIMM releasing them from the board. Remove both and set them aside.
Eighth, install each 4MB SIMM by inserting at a 45 degree angle and leaning back until held in place by the metals clips.
Ninth, reinsert the circuit board into the slots on the Mac frame and reattach the connectors as well as the CRT cap (very carefully!).
Tenth, reassemble the case with the Torx screws.
Finally, it is time to boot the Mac and check the reported RAM. Online instructions say to clear the PRAM on the first boot. This is done by holding down the Command, Option, P, and R keys together while booting. Continue holding the keys until you hear the startup chime for the second time. Then release the keys and to let the boot process proceed normally.
Comments
An easy and inexpensive project that maxes out this classic Mac.
