imac g3 booting with firewire

As the owner of 3 iMac DVs, 2 of which bit the dust from excessive heat destruction of the PAV board (an all-too-common failure), I have to ask what your realistic expectations are for this 24 year-old Mac? Has your son played games on faster/more responsive computers? If so, the iMac will be quite sluggish by comparison. Hardware that's a quarter of a century old is ancient in terms of the technology. Fifteen+ years ago, I used an external Sony (FireWire-only) CD-RW drive to boot my iMac, so it is possible to boot from a FireWire optical drive. LaCie doesn't manufacture the optical drives in their enclosures. They use a variety of third-party drives and install them in their enclosures. The LaCie DVD±RW drives that you referenced [300986 and 300987] are compatible with OS 9.1 or later (although certain functions require at least OS 10.2.3), but they require a 500 MHz G4 processor minimally. From their product spec sheet:

You really only need an external CD-R/RW drive for installing the OS, because every OS version up until Tiger was installed from CDs, not DVDs. Another problem with third-party optical drives concerns being recognized by those older Apple computers for booting. They might function normally with the exception of being able to boot the iMac, even after being selected as the startup device. I wouldn't recommend investing a lot of money in that iMac in 2024. A used 2000 iMac DV has uncertain remaining service life, due to the inadequacy of its convection cooling design and years of use. That's why so many failed - and many years ago at that. The main power component (the Power-Analog-Video board) fails from prolonged overexposure to the heat. When it malfunctions, you'll press the power button and hear a barely-audible "pfffff" sound and the iMac won't boot. There are no new parts being made and the replacement procedure is too involved and time-consuming to pay for professional replacement with a used part. Because it's located in the high-voltage area of the chassis, replacement requires an experienced CRT-tech. I upgraded my iMacs with larger-capacity hard drives and maxed the memory at 1 GB, but that was almost 20 years ago. With 2 of them having been e-cycled, I wouldn't consider doing so today. Sorry to sound pessimistic, but I'm basing my comments on personal experience.

As for the internal DVD-ROM drive not working, when you insert a disk into the slot, do you hear the motor running as it attempts to grasp the disk or is it completely dead? The main problem that developed with those slot-loading optical drives was related to age and a drying out of the rubber-clad rollers that pull and eject the disks. As their surface gets dry/slick, they lose their capability to grasp disks. Replacement with a used/pulled optical drive could produce the same result.

Hi,

An external FireWire CD or DVD drive ought to work, but you may want to double-check that with the supplier. An external FireWire hard drive with a valid Mac OS 9.x system should be OK. Alternatively, if you have access to another Mac with FireWire, you could try FireWire target disk mode. It may even be possible to boot this slot-loading model from an external USB hard/flash drive containing an appropriate Mac OS 9.x system.

https://everymac.com/systems/apple/imac/specs/imac_dv_se_500.html

Is this your iMac?

If so, Mac OS 9.0.4 appears to have been the pre-installed version.

The general rule is to use a later retail (neither machine-specific nor update) disc.

See also https://en.wikipedia.org/wiki/Mac_OS_9#Compatibility.

Others here may be able to provide additional details.

Regarding the internal optical drive, what kind of problem does it have?

Since you mentioned OS 9.2.2 earlier, do I understand "there is not a single software on the computer" just as it reads? That is, the hard disk is completely empty/wiped, and not even a minimal system. Or is it actually possible to boot the machine today?

FireWire is gonna be the best way to boot an iMac especially if it's an ssd drive in an enclosure try it you'll be blown away by the responsiveness of the Mac after it's booted from FireWire external ssd