iMac G3 Slot Loader Upgrades

imac slot front

This page covers all the upgrades we sell for iMac G3s with a slot loading CD/DVD drive. Choose the type of upgrade you are looking for from the tabs below. (Not the right Mac? See here for more iMacs, or here for all Macs.)

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If you want specific upgrades for your exact model, choose it from the Model ID links below, or enter your serial number here:

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imac slot side view


Apple revamped the iMac in late 1999. Both the internal and external components changed greatly. It became a very popular range of machines which sold in the millions.

Internally they went for a whole new logic board with FireWire and Airport sockets on all except the earliest revisions. The motherboard changed to a 100MHz board which accepted the cheaper and larger SDRAM DIMM memory, instead of SODIMMs as used on the tray-loading iMac.

The CD-ROM was replaced with a slot loading version (which became a DVD-ROM and CD-RW on later models).

Later machines were announced with speed bumped processors, more VRAM and some interesting choices of colours.

It was the iMacs distinctive colouration that set it apart from the rest, and is still being imitated today. However some of the outrageous colours, including "Blue Dalmatian" and "Flower Power", did not go down as well as others!

How to Identify these Machines

The iMac G3 Slot Loader is distinctive in its appearance. There were three types made, all with different processors, RAM and colouration.

The G3 iMac series can be distinguished by their optical drives. These G3 iMacs have a slot loading optical drive. The earlier machines have a tray loading CD optical drive.

The vast majority of the slot-loading iMacs had a FireWire port. However the first model, the 350MHz version, does not have FireWire.

Although this page covers a number of versions, all the upgrades available are the same.

If you are still unsure you can contact us on 01223 833 412, or by email, for confirmation. If you want to upgrade but aren't happy to install your upgrades then we can help. Simply ask our engineers for further details.

Memory Upgrades

The iMac G3 slot loader has 2 memory socket available for upgrade. It can accept up to 1GB of RAM in 2 x 512MB chips.

There are none available.

Difficulty 2 / 5 - Easy

Turn off the machine and remove the power cable.

Turn your iMac so that the Display is facing the surface (a soft cloth can reduce scratching).

On the underside of the machine there is a small circle in the same colour as the rest of the iMac. This (with a coin) can be turned to the unlocked position to reveal the RAM sockets. These SDRAM chips will only fit in one way round and are secured, with clips, on the end of each RAM modules.

Apple's fitting guide is here.

CD/DVD/Blu-ray Drive Upgrades

The iMac G3 Slot Loaders came equipped with either a CD-ROM, DVD-ROM or CD-RW optical drive on the front of the machine. At present we don't stock internal CD or DVD writers for this machine, but it is possible to use an external device via USB or FireWire (FireWire is better if your iMac has it).

There are no optical drive upgrades available for these Macs

Difficulty 1/5 - Very Easy

Install any supplied software.

Restart machine and connect the new device.

Internal Hard Drive & SSD Upgrades

This range of drives will work in your iMac G3 Slot loader, although user installation is difficult (see below). Please note that internal hard drives larger than 120GB will not work in this machine.

If you don't want to fit a new hard drive yourself, you can take advantage of the MacUpgrades Installation Service. Add the installation service from the list below to your cart along with your chosen hard drive. We can also clone your existing hard drive onto the new one, simply add the Clone Original Hard Drive service below to your cart.

Once you have booked the service, send your machine to us, we will carry out the work and return it to you. Alternatively, we do offer a Collection Service with our courier, please see here for details.

There are none available.

Difficulty 4 / 5 - Reasonably tricky.

WARNING: The iMac has a CRT tube which can store a build-up of electrostatic charge. These instructions assume you know and understand this danger.

Turn off the machine and remove the Power cable.

Turn your iMac so that the display is face down (a soft cloth can reduce scratching).

The bottom case is secured with two screws which are located near the feet of the stand. Remove these two screws.

The next screws are hidden beneath the VGA port cover. To the rear of the machine there is a cover dotted with holes. With a flat blade screwdriver this can be gently pried out. This reveals 4 screws. Remove the outer set of screws. With a gentle tug you can then remove the bottom case of the iMac.

This reveals a metal grill which covers the whole machine. This grill is held in place with 6 screws dotted around the base of the metal grill. WARNING: these screws have a habit of falling into the case when being screwed in or out - if this happens you must remove them before restarting, or you risk damage to your iMac. Once the screws are out the grill can be gently lifted out.

The next job is to remove the RAM which is housed in the long black sockets secured with clips at either end.

The hard drive is connected with 2 cables, one coloured and one of a ribbon type. Remove these cables.

The drive is held in place with 4 screws (flat Phillips head) gently remove these and the drive will release. Replace drive and reassemble machine.

Start from CD (hold down 'C' key on startup) and initialise the drive.

If you are unsure we can install the drive for you. Please contact our team for details.

Graphics Cards and Displays

The graphics card in your iMac G3 Slot Loader is part of the main logic board. Unfortunately therefore it is not possible to increase or change the graphics card. It may be worth expanding your memory to its maximum to try and compensate, although this will have a limited effect at best on your iMac's 3D capabilities.

There are no graphics card upgrades available for these Macs

Expansion Card Upgrades

Your iMac G3 Slot Loader has no available PCMCIA or PCI sockets for connectivity expansion.

There are no expansion cards available for these Macs

Keyboards & Mice

The following keyboards and mice are compatible with this Mac.

Trust 3 button USB Optical MouseStock: Available£6.75 + vat (£8.10)
Cherry Strait 3.0 USB Keyboard - UK Mac LayoutStock: Available£32.00 + vat (£38.40)

Power Supplies & Batteries

Listed below are power supplies, batteries and related products we supply for this Mac.

3.6V (half AA type) Lithium PRAM/Clock Battery for MacStock: Available£9.00 + vat (£10.80)

Any fitting information below is intended as a guide before purchase ONLY, when fitting these products you should refer to the original manual for your computer, and any instructions that come with the item. Please see this page for more information, or here for information on our fitting service.

Cables & Tools

Listed below are power cables, tools and related products we supply for this Mac.

Cables & Adaptors

FireWire 400 - 800 Adaptor Cable M/M (6pin - 9pin) 6 ftStock: Available£11.00 + vat (£13.20)1


Precision Screwdriver Set, 31 Piece - Phillips/Torx/TR6Stock: Available£12.50 + vat (£15.00)
Anti Static Wrist StrapStock: Available£8.50 + vat (£10.20)
1For models with FireWire ports.

External Drives & Enclosures

Versions of this Mac which have FireWire can use any of the following external hard drives. If you don't have FireWire then unfortunately your only option is to use normal USB - this is a very slow connection for data storage, and is not generally recommended.

There are none available.

Complete Machines - Refurbished

Any complete machines of this type or similar that we have for sale are listed here. Please note that these are refurbished models with a 3 month warranty, and that delivery is likely to take 3 - 5 working days. These can be purchased online with the standard website courier delivery charge for the mainland UK only. Please contact us for a quote on shipping to other areas.

Repair Services for this Mac

Here are the various repair services we offer for this Mac. You can have us take the machine in for evaluation, or book a fixed-price repair if you already know what the fault is and the service is listed below (for services without parts, please see the relevant tab on this page for compatible parts that we sell). If you know what the fault is, but we don't have a fixed-price repair listed below, please contact us for a quote.

Evaluation Services

Mac Repair - Evaluation ServiceStock: Available£39.00 + vat (£46.80)

Installation Services (parts not included)

Collection ServiceStock: Available£24.68 + vat (£29.62)