Adding Memory to Mac OS X Snow Leopard

By Mark L. Chambers from Mac OS X Snow Leopard All-in-One For Dummies

If you’re familiar with the inside of your Macintosh, you can install your own memory upgrade and save that cash. A memory upgrade is one of the simpler chores to perform, but that doesn’t mean that everyone feels comfortable taking the cover off and jumping inside a computer; hard drives are a tad more complex.

If you have a knowledgeable friend or family member who can help you install your hardware, buy him the proverbial NSD (short for Nice Steak Dinner) and enlist him in your cause. Even if you still do the work yourself, it’s always better to have a second pair of experienced eyes watching, especially if you’re a little nervous.

Because the installation procedures for both memory modules and hard drives are different for every model of Mac, step-by-step procedures aren’t included here. Many online stores include installation instructions with their hardware. Other sources for installation instructions include the Apple Web site and your Apple dealer. You can use Safari’s Google search feature to scan the Internet for installation information for your particular model. However, here are guidelines to follow during the installation:

Watch out for static electricity: When opening your Macintosh and handling hardware, make certain that you’ve touched a metal surface beforehand to discharge any static electricity on your body. (You can also buy a static wrist strap that you can wear while working within the bowels of your Mac.)
Check the notches on memory modules: Most types of memory modules have notches cut into the connector. These notches make sure that you can install the module only one way, so make certain that they align properly with the slot.
Make sure you’re using the right memory slot: Most Macs have multiple memory slots, so check the label on the circuit board to make sure that you’re adding the memory to the correct slot. (Naturally, this won’t be a problem if you’re installing a module into an unoccupied slot.)
Take good care of older hardware: If you replace an existing memory module or hard drive with a new one, put the old hardware in the leftover anti-static bag from your new hardware and immediately start thinking of how you’ll word your eBay auction . . . Used 1GB Memory Module for Intel iMac, for example.
Check your hard drive jumper settings: If your Mac uses EIDE hard drives, you must set the Master and Slave jumpers correctly on the back (or underside) of the new drive. A jumper is simply a tiny metal-and-plastic connector that is used to change the configuration on a hard drive. Setting jumpers indicates to your Mac which drive is the primary drive and which is the secondary drive.

If you’re adding a second drive to a desktop with an EIDE drive, you’ll probably have to change the jumper settings on the original drive as well. (If you’re replacing the existing drive, you’re in luck; simply duplicate the jumper settings from the old drive and use them on the new drive.) Because the configuration settings are different for each hard drive model, check the drive’s documentation for the correct jumper position.
Leave the cover off while testing: After you install the upgrade, leave the cover off your Mac (if possible) while you boot the computer and test to see how well you did. That way, if you have to replace the original hardware for some reason, you won’t have to remove the cover a second time.

To determine whether a memory upgrade was successful, you can again turn to the Apple System Profiler. Open the Profiler and compare the memory overview specifications with the original list that you made earlier. If the total amount of memory has increased and the memory module is recognized, you’ve done your job well. If not, switch off the Mac and check the module to make sure it’s completely seated in the slot.