I have an old iMac 400MHz slot-loading G3 model #M5521 that won't power up (think it's a dead power supply), and I'm trying to get the data off my hard drive. I also happen to have a 333MHz tray-loading G3 model #M4984 and am wondering if I can put the HD from the 400MHz into the 333MHz, just to use to boot up and back up my data onto a flash drive.

Here are the specs: iMac #1 (the one with all my data on it): 400MHz slot-loading G3, Model #M5521, 20.4GB hard drive (may not be the original HD - think it originally came with a 13GB), 320MB memory (256 and 64 cards), dvd drive, serial #RN9445BXHCW, and is running OS 10.3.9. The hard drive says on it: Maxtor HD model # 92049U3, 20.4GB, manufactured 15 July 2000.

iMac #2: 333MHz tray-loading G3, Model #M4984, 6GB hard drive, 288MB memory, CD drive, serial #XB9361VUGSQ, and is running OS 9.2.2.

The questions we have are whether the 400MHZ iMac hard drive can be put into the 333MHz iMac and, if so, whether it would be able to boot/run it given it is running OS 10.3.9. We are trying to do this ourselves, as we are money-limited, and my husband is capable of changing the hard drives, however the 333MHz iMac is the only other machine/method we have to use to try to recover the data. Any info you could provide on the compatibility of the two hard drives/iMacs would be very much appreciated.

Thanks a lot, Cindi


Well, while newer iMac drive will work in older one, there is no guarantee it will boot.

There was a limitation during the times of Classic Mac OS on size of boot partition which has to be below 8GB. You have Mac OS X 10.3.9 on that drive so I can't say if it still applies. And maybe if it does apply you might had it partitioned just the way it need to be to overcome it.

Then again getting HDD from that iMac and into it is not that easy. Not that it really hard but still it is not a Mac Pro or standard PC case.

And also keep in mind that you might just break cables when disassembling since it is long time when it was put together and they probably aged and aged cables don't like when you bend them.

So if you are not afraid of the idea of making another iMac unusable or brave, experienced or just curious then go ahead and try. Do not forget to remove power cord, then press power button to get excessive electricity from capacitors off and get yourself grounded.

Still there is an option and it is just buying a used (they are cheap since practically nobody use them) or getting for free a USB enclosure (it could be USB 1.1 or USB 2 — it doesn't matter since that iMac only has USB 1.1 ports anyway yet USB2 enclosure will work too. It even can be 5.25" external CD case provided it internally uses PATA/IDE interface) case for 3.5" PATA/IDE HDD.

After putting your HDD into it you should see content of it. Provided it is not dead, of course.

So good luck and keep us posted.

  • Would this hard drive case work with the computer and HDD I have? newegg.com/Product/Product.aspx?Item=N82E16817182153 I'm not experienced at buying computer parts and want to make sure I'm getting the right item. Thanks a lot! – cindi Dec 20 '14 at 6:05
  • I don't see why not. Though you might also check classified ads on computer equipment for your city and might just get used case for few bucks or even free if it will be USB1.1 – iskra Dec 20 '14 at 19:33
  • @cindi the proposed case is technically the correct one. Fighting through the tons of reviews of this product at newegg.com the probability of failure (dead on arrival, missing/non-fitting screws/weak power supply) is not low. So check for a customer friendly return policy... – klanomath Dec 20 '14 at 19:37
  • Question -- If I do decide to do the hard drive transplant, I read somewhere that there might be a limit on the size of the hard drive that the 333MHz iMac could handle (maybe a limit of 8GB?). Does anyone know if that is true or would be a problem? Thanks. – cindi Dec 21 '14 at 2:56
  • This iMac can handle any IDE drive up to 120GB. I encourage you to read my answer since it answer the question already. P.S. And then I recommend you just buy HDD case – iskra Dec 21 '14 at 4:11

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