How to tell if a Bondi iMac is Rev. A or Rev. B
I was given an iMac recently, and decided to burn a little cash on upgrading it. However, I had a problem. I knew I had a Bondi iMac, but I couldn't tell if it was revision A or B. They're both teal, they have the same form factor, and there are no visible markings to differentiate them.
It does make a difference when upgrading. For example, the revision A iMac can only use up to 384 megs of RAM, while the revision B iMac can take 512 megs of RAM.
It has been nine years since the original iMac arrived on the scene, so my assumption was that this is a solved problem. I'd hop online, search for a hint, and discover an easy way to tell the difference between them. But no, it's not solved. However, it turns out that it can be solved, pretty easily.
The Hard Way
There are Web pages that discuss this issue. Apple's official page, "iMac: How to differentiate between models," mentions some characteristics of each model, but fails to tell you how to find those things on your computer. For example, it mentions that revision A uses a Rage IIC video chip, while revision B uses a Rage Pro video chip. Umm... does that mean I have to disassemble the computer to inspect the video chip on the motherboard? If so, I'm not interested, and you probably aren't interested either. Another site suggests looking at the part number, but I couldn't find that number anywhere on my iMac, and they don't give you hints.
The Easy Way
With some work I boiled all the reading I did down to two simple, obvious ways to tell if you have a revision A or B iMac. Here's the first way: flip it over and examine the FCC sticker. If you see the text "Rage Pro/6MB" then you have a Rev. B Bondi iMac.
The second way is probably more useful if you're reading this with your iMac right now and don't want to flip it. Using OS 8 or 9, select the Apple menu in the upper left corner of your iMac's screen. Then select "Apple System Profiler." In the window that appears, select the "Devices and Volumes" tab. Down near the bottom of the window will be the PCI device listing – in particular, "Slot $ATI." Click the little disclosure triangle to show the details of the display card. If the card name is "ATY,RagePro_C" then you have a Revision B Bondi iMac. If the card name is "ATY,RageIIC_C" then you have a Revision A. If you see something else, then you probably don't even have a Bondi iMac. You might have a blueberry iMac, which is a later and better model. Lucky you.
Bondi iMac photo by Terry Hefferman. Courtesy of Apple Computer, Inc.