Tech Tips
My Mac Magazine #26, June ’97

Tech Tips dives into the not-so-bottomless pit of computer memory for this installment. We’ll discuss the different types and provide a few pointers to aid in deciding if you have enough computer memory and what to do about it if you don’t.

Now, before I go any further, let’s get the standard cliches out in the open: Do you have enough memory – no I forget. Geez, I didn’t know I could buy the stuff – I’ll be able to remember my wife’s / girlfriend’s / ex-roomate’s birthday, etc., etc. Don’t misunderstand, I love a good joke. Heck, I’m on 3 humor lists, but after you hear ’em for the 400th time they get old.

Differences in memory. You do realize there are two types of memory, right? There is RAM (Random Access Memory) and storage space (usually referring to hard drives). RAM is where the computer temporarily stores programs while you actually use them. Storage space is where the programs actually reside, somewhat permanently, in the computer. Storage space also covers items like floppy disks, removable storage like Zip disks, CD-ROMs, digital tapes, and other types of magnetic media. RAM is silicon chips that can be permanently affixed to your computer’s logic board and also in the form of memory modules (commonly Single Inline Memory Module and Dual Inline Memory Modules, i.e., SIMM and DIMM). If anyone has a better, down-to-earth, explanation , I’d love to hear it!

What is the actual user relationship to either types of memory? Well, if you use more than one program at a time or get a message when actually trying to use a program to the effect that there is not enough memory available, then you’re having RAM problems. What has happened is that RAM has a limited capacity and the program(s) you are using have used all of it up. Many solutions to this problem are available, and have been discussed in previous issues, but they all indicate you must increase the amount of RAM available to programs by either using less (or smaller) applications or physically adding more RAM.

With storage space, as with RAM, there is a finite limit. The more programs that you store on your computer the more space will be used up. If you try to add a new program, download a file, or save a huge Photoshop document and get a message like “error disk full,” it means that you have to somehow create more available space. One method is to delete items from your hard drive that you no longer use. Another is to replace your existing hard disk with one or greater capacity or just add an external hard disk or removeable storage to your Mac. Compression software is another alternative (although I recommend against many of them when one considers the current low prices of hard drives).

Here are a few quick tips to see how much memory you have. To find out how much RAM you have, pull down the Apple menu and choose the first item “About This Macintosh” (or Computer or Finder). The window that appears indicates what version of Mac OS your computer is running, plus how much memory is available and what is left for applications to use. The total memory, or Built-in memory, should be listed in K, or kilobytes. Roughly divide the number by 1000 and you will know how much RAM your computer has installed in it (actually 1 Meg is 1024K if you really want to know). The other information will provide you with what programs are running and how much they are using, plus how much of the memory is left for other programs to use.


Tech Tips Picture 1It’s just as simple to determine how much storage space is available. Open your hard drive’s icon and look at the top of the window. If you don’t see information about the quantity used and available, pull the View menu down and select “By Icon” – the usage info should be displayed, with the amount used on the left and the space available on the right.


Tech Tips Picture 2If you determine that you need more RAM, decide if you want to use a software product like Ram Doubler or Apple’s Virtual Memory (built into the OS) or if additional physical RAM should be added. If you decide to add physical RAM, the steps vary widely and would take up an entire column – suffice it to say check with newsgroups/e-mail lists or contact a vendor (make sure to tell them what model and how much RAM you currently have).

If storage space is what you need, consider adding an external device like a Zip drive or an external hard drive. The decision process is a little easier here since 99% of all storage devices will work with any Mac made since the Plus; you only need to decide if you want fixed capacity (as with a hard disk) or unlimited capacity (like a Zip drive).

Real World Experience

The System: Performa 475

The Problem: America Online Internet Browser doesn’t function.

The Solution: Increased RAM from 8 Megs to 20 Megs.

The explanation: This was a very straightforward fix. The OS was using ~3 Megs of RAM, AOL wanted ~2.5 Megs to run acceptably and the Internet browser needed an additional 2 Megs. Although the three don’t add up to 8 Megs, when you consider the increase of system memory usage with the modem overhead and other minor discrepancies, it was clear that additional RAM was needed. Installing a 16 Meg SIMM and increasing the memory allocation to the AOL applications not only cured the problem but greatly improved performance.

Jeramey R. Valley (

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