Until the ATAPI 6.0 (ATA-6, ATA/100) standard, IDE drives on mostly any computer were limited to a capacity of 137 GB. The first Mac to supersede this limitation was the Revision B Quicksilver Dual 1.0 Power Mac G4 (Logic Board 820-1342-B), whereas the first iMac with Ultra ATA/100 was the 1 GHz 17″ from 2/4/03.

Last weekend I picked up a $2 500 GB Maxtor ATA/133 Hard Drive, recognizing it from how similar it looked to a 300 GB Maxtor I already have, believing it would be just as reliable (Thank you Stan!). In addition to the Power Mac 9600/300 Dan Bashur gave me, I also got a few other Macs including a 400 MHz Indigo iMac G3 from Summer 2000. Still has it’s original boot ROM (3.3.0f3), and a June 19th, 2001 purchase date according to Apple coverage.

With SpeedTools Hi-Cap ATA Driver, this allows you to remove this limitation on certain Macs – including this Indigo 400 Mhz iMac G3.

Getting Started

At first I had an 80 GB WD Drive in the iMac, thinking I’d install Tiger, then install the driver, clone to a 500 GB HDD over firewire to an enclosure, swap drives and be done. The driver must be installed first before formatting or interacting with >128 GB drives, or they won’t show up properly.

I realized it would be simpler if I had an existing machine running 10.4.11 to use as a boot volume via target disk mode, with the 500 GB Maxtor pre-installed in the iMac – all I’d have to do is install the drivers on the iBook I’m booting from. This is software I purchased 15 years ago from their website.

Now with the Hi-Cap ATA drivers installed, the 500 GB Maxtor IDE/133 HDD is in! Once it’s cloned, this iMac G3 will run Tiger on plenty of drive space. The drive gets formatted and wiped as a part of this process, and I also formatted in Disk Utility before using CCC to be sure any old data couldn’t be read, although it was already blank.

Since the iMac G3 was booted + was cloning the drive w/Carbon Copy Cloner 3.4.7 via FireWire 400 off a 500 Mhz iBook G3, it took 6 hours to copy a mere ~14 GB. As soon as it was done, I was able to select the 500 GB drive as a boot disk in system settings and restart without issues.

After the Reboot

Without performing any extra startup sequences or even adding to the boot time, this 400 MHz Indigo Summer 2000 iMac G3 ran entirely off the upgraded drive – well beyond in capacity than what the iMac initially supported.

I’ve had good luck with this specific era of Maxtor drives, still also have a working 300 GB which looks so similar to this, I believe  had that one since ~2010. Got my fingers crossed! In any case if it dies, drive backups are a must. WD has also been good to me, I like their enterprise grade drives. I’ve heard bad things particularly about the WD green HDD, but I have a 3 TB WD Green what’s survived since 2013 A-ok.

And it was a success!

What sparked the idea?

For fun of course! I picked this drive up for only $2, and figured it would go with some sort of project. An easy way to pump up the stats of this old indigo 400 MHz FireWire iMac. I also suppose rather than an SSD I chose this drive as it was low-cost, and feels right for what this project is.

I know my eMac has a 128 GB mSATA, it’s certainly quieter, but this’ll do fine for the large swathe of storage it provides. Lately I’m seeing more community-developed PowerPC software such as PowerFox for G3, exFAT support for tiger, a PowerPC Claude Agent, and other interesting bits, so I wanted to put together a G3 machine specifically running Tiger.. although I’m already thinking of putting multiple partitions and OSes on here.

Someone in the Low End Mac community brought to my attention; The Boot ROM of this iMac is very out of date and it should be dumped/saved, I did this and uploaded it to MacRumors. (3.3.0f3)

Running the Serial number on Apple’s coverage site confirms the purchase date and age of the iMac, but it shows up as a pair of AirPods Pro. On Appleserialnumberinfo.com, the serial number doesn’t exist. In any case, it’s gonna be fun to see what this iMac can still do!