Ram Slots on Imac 266mhz Rev C

The two SO-DIMMs that you see are different: One is the system memory installed in the upper memory slot on the processor card, and the other is a 4 MB SGRAM SO-DIMM that upgrades the 2 MBs of onboard graphics memory to 6 MBs. There is a second memory slot that's hidden from view, because it's located on the underside of the processor card assembly. Do you know for certain that a single 128 MB SO-DIMM is installed? You may discover that there are (2) 64 MB SO-DIMMs installed - one in the upper slot and another in the lower slot on the processor card assembly. The Apple System Profiler will indicate if both slots are occupied, and if that's the case, you'll need to remove one of the 64 MB SO-DIMMs. You could take the easy route and pull the one in the upper slot, or if you'd like to remove the processor card assembly to access the lower slot, illustrated instructions can be found here. SO-DIMMs installed in the lower slot must be the low-profile type, but can also be used in the upper slot. While comparing prices, check out this dealer's memory for tray-loading iMacs.

You can use this handy web page at OWC.

http://eshop.macsales.com/MyOWC/index.cfm?StartOver=1&TI=5006

$39.95 for 256mb low-profile. Not bad. I paid a lot more...

Hi, Im doing the same for my girlfriends old and prize possession imac G3,slot loading,cd rom,400mhz, blue/white...going to fill up the ram with a view to backing up everything first on an external hard drive, then wiping the imac drive clean and then installing OS panther...I'm a (huge) bit wary as not done any of this before any advice on the entire procedure???
Ive picked up on the firmware update before anything else, she's currently running OS 9.2.1....Really would appreciate a step by step idiots guide to doing the whole operation..Reformatting hard drive etc...where to start...Help!! Its not had any tlc for ever and is running all over the place...Ive just been given mac OSX 10.3 discs 3xinstall discs and 4xsoftware restore discs and hardware test cd...they are all marked for an iBook G4....Can I use these to upgrade from OS 9.2.1?? Any help at all would be greatly appreciated..thanks

If you're using a stock Revision A-D iMac and you want to bump the RAM, you might well look into also boosting the processor. Right now on good old eBay, Sonnet Technologies is clearing out their G3 600 MHZ + firewire 400 Harmoni upgrades at (drum roll, please) $149 plus $10 shipping. I was about ready to donate my two Revision D machines to starving children in Guyana when I saw this (you see, I'd just bought my wife one of those nice new metal cased 20" iMacs, and I had a serious case of computer envy going on), and I took the plunge on one. Took about half an hour to install (I've had my iMacs apart more than a few times, for RAM and hard drive upgrades, so it was easy for me). I moved my 512 MB of RAM from the old CPU card to the Harmoni, popped it in, and suddenly I'm cruising along with OS 10.3.9 for a change (you need to find yourself a CD install of 10.3, which might be a bit of a hassle, since it's mostly out there on DVD these days). My point is that if you're going to crack the shell to pop in a RAM card or two, why not do three things at once, to actually make the machine somewhat more up-to-date with this VERY reasonable upgrade? The RAM is cheap, and the processor upgrade (it's "buy it now" only, with something like 20 units per posting, and they're not moving particularly fast, even at only 50% of retail price--I think that OWC still offers them at their full retail price of $289). Plus you get the firewire port, which opens up large external HD connectivity options and maybe (haven't tried yet) DVD R/W drives. I'd recommend that if you want to bother with the RAM boost (and the chips ARE fairly cheap, as pointed out by others) you can make the machine live another 3 - 5 years by slapping in a Harmoni and a bigger HD (60, 80, or 120 GB are the best options, but make sure that the HD is compatible first!). Even with maxed-out RAM at 512, OS 10 runs like a pig on Rev. A-D, but with a bigger HD (follow the formatting guidelines EXACTLY, and make your first HD partition--for installing the OS--less than 8 GB) and the seemingly small speed boost from 233, 266, or 330 Mhz up to 600 Mhz, your colorful desktop buddy will purr. Worked so well, I did it again on my second Rev. D machine...

Just a warning reminder, though... if your original iMac is slot-loading (350 Mhz or faster CPU), there is NO upgrade available for the processor. Funny how sometimes it pays off to be a little bit more primitive...

I remember the days of shouting "Apple ][ Forever!" Now I wonder if it's going to change to "Tray-loading iMacs forever!"...

Naturally, now that I've already posted that it's impossible to boost a CPU in a 400 Mhz iMac, I actually bothered to look around.

Can't recommend this company, because I've never done business with them, but I found this link to a place that says they can change your 400 Mhz G3 into a 550 Mhz G4:

http://daystar-store.com/index.asp?PageAction=VIEWPROD&ProdID=317

They also offer to install the RAM upgrade. Caveat emptor.

In addition to the Daystar upgrade, there is the one from FastMac

http://fastmac.com/imacslot.php

I haven't used this upgrade, but I have their (apparently no loner available) G4 467 MHz upgrade for the tray-loader iMac. It's been operating well for years. I also bought their G4 550 MHz upgrade for the Pismo. It's about 8 months old and working fine. If you can attend MacWorld Expo in San Francisco, FastMac has a booth. I bought both there (different years) for a substantial discount price.