400 MHz iMac G3

There were four different G3 iMacs that ran at 400 MHz: two introduced in 1999, one in 2000, and one in 2001.


The 400 MHz iMac DV and 400 MHz DV Special Edition were introduced in October 1999. These included a DVD-ROM drive and were the first iMacs with built-in FireWire. They have RAGE 128 graphics with 8 MB of video memory and run Mac OS 8.6 and later. The DV model came in five “fruity” flavors – grape, blueberry, strawberry, tangerine, and lime – while the DV SE shipped in graphite.

The summer 2000 400 MHz iMac DV dropped DVD-ROM in favor of CD-ROM to keep costs down. It was available in indigo and ruby and requires Mac OS 9.0.4 and later. Graphics were improved with the Rage 128 Pro chipset.

The final 400 MHz iMac was the early 2001 model, available only in indigo. It shipped with Mac OS 9.1.

Mac OS X

Non-Apple upgrades and peripherals (such as unsupported USB devices, replacement drives, and third-party memory) may cause problems when installing or booting into Mac OS X.

Be sure to read and follow Apple’s “Read Before You Install” install instructions to increase the likelihood of getting OS X installed and running on the first try.


  • CPU: 400 MHz PPC 750
  • Bus: 100 MHz
  • RAM: 64 MB, expandable to 1 GB using two PC100 SDRAM (3.3 V, 64-bit, 168-pin, 100 MHz)
  • Video: supports resolutions of 640 x 480, 800 x 600, and 1024 x 768
  • Display: 15″ CRT (13.8″ viewable) multiscan to 1024 x 768
  • L2 cache: 512 KB 160 MHz (5:2) backside cache
  • Hard drive: 10 GB EIDE drive (13 GB for DV SE). Maximum IDE drive size is 128 GB without third-party support. See How Big a Hard Drive Can I Put in My iMac, eMac, Power Mac, PowerBook, or iBook? for your options.
  • DVD-ROM: 4x
  • CD-ROM: 24x
  • SCSI: none
  • PCI slots: none
  • USB: 2 separate USB 1.1 ports and controllers
  • FireWire 400: 2 ports
  • Modem: built-in v.90 56k modem
  • Ethernet: 10/100Base-T
  • WiFi: 802.11b AirPort Card, requires AirPort Card Adapter
  • Microphone: internal
  • Power supply: 150W
  • PRAM battery: 3.6V half-AA
  • Height: 15.0 in/38.1 cm
  • Width: 15.0 in/38.1 cm
  • Depth: 17.1 in/43.5 cm
  • Weight: 34.7 lb/15.8 kg
  • family numbers: M5521

Online Resources


  • You cannot plug the iPod shuffle directly into the iMac’s USB port – it will not fit. It will not charge if plugged into a keyboard USB port or an unpowered USB hub. To charge it while using it with your iMac, you must us a USB extension cable, powered USB hub, iPod shuffle dock, or a USB power adapter.
  • Update Firmware Before Installing Jaguar!, Geoff Duncan, TidBITS, 2002.10.28. If your firmware isn’t at version 4.1.9, you need to boot into OS 9.1 and install it before attempting to install Jaguar (OS X 10.3) on your slot-loading CD-ROM or DVD iMac.
  • You must have the keyboard plugged directly into an iMac USB port to boot with the power key; it will not work if the keyboard is attached to a hub.
  • You cannot boot the iMac from an external USB drive.
  • The iMac loads the MacOS Toolbox into RAM, unlike other Macs which use it from ROM. You lose the use of 3 MB of memory but gain faster performance.

keyword: imac400