Task: Upgrade a Macintosh LC Computer to 10MB of RAM
Needed: Two 4MB RAM SIMMs
Time: 15-30 minutes
Introduction
I acquired a Macintosh LC 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 Mac LC came out in 1990 and was sold through 1992 mostly to schools. It came with a Motorola 68020 processor, but Apple decided to downgrade the data bus to 16-bits as they did with the Classic II. This means the system can only address a maximum of 10MB of RAM. The LC comes with 4MB of onboard memory. 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. This project is very similar to the RAM upgrade I did with my Classic II and uses the same 4MB SIMMs.
Instructions
First, purchase two 4MB SIMM cards that are compatible with the Mac LC. I got mine from Keystron on eBay for $15. Compatibly includes 30 pins, non-parity, and faster than 100 ns.
Second, open the Mac LC by gently releasing tabs on the back of the top case cover and slide it forward revealing the circuit board and other components such as the floppy drive, power supply, and hard disk.
Third, locate the two empty 30-pin slots on the right side of the circuit board as you face the front of the computer. As shown below, these two slots are right next to a longer slot with a Video RAM board in it. There is no need to remove the circuit board from the case.
Fourth, insert one SIMM in the left (back in photo below) slot at a slight angle with the chips facing to the right in the same directions as the chips on the VRAM board. Tilt the SIMM to the right (forward in the photo below) until the silver metal clasps lock it in place. A little pressure is needed. Insert and lock the second one.
Fifth, reassemble the top case applying gentle pressure to the clips in thew back that hold it down. They can break so be careful.
Sixth, power up the Mac and open the About window from the Apple icon to see the new RAM total. It should have a number just about 10,000K as shown below.
Comments
As with the Classic II, this is an easy and quick install and at $15 the price is right. I ordered a 32MB SIMM to upgrade my LC III and it was about $12. I will post about this upgrade later.
Note that my Mac LC actually has an LC II motherboard in it. However, the slots should look the same as a stock LC board with no install differences.
I have previously covered how to get Mac LCs to display video on an LED monitor via VGA to HDMI.
