iMac G3 LAN Setup

In June of this year (2024 at time of writing) I had a break from study, so naturally I decided to setup a LAN for my iMac G3s.

Hold up. Why is this special or even interesting?

The reason this whole idea is at all interesting is because iMac G3s are notoriously difficult to network together, due to the fact that they require twisted Ethernet cables, and there are lots of incompatibilities between OS 9 and OS X, including file sharing and networking.

It started out by finding a network switch to use. I had a TP-Link 5x port switch which I initially used for my mum's PC and my own laptop, but the flat Ethernet cable I used seemed to stop working, so I removed it from its home under my desk, and started a test run between my Graphite and Indigo iMac G3s.

While setting up the test run I ran into an issue. I only had a single twisted Ethernet cable (a red cable from years ago) which I used to connect my Grape and Graphite iMac together, but that setup only allows for two iMacs to be networked, not three.

After this realization I went and got another (non-twisted) Ethernet cable in the hopes that it might work anyway.

Upon powering up and booting up the file sharing extension on OS 9, I found that it actually worked! This was quite exciting.

This did call into question the whole twisted-cable issue from before though. Why was it working now? I came to the conclusion that the iMac G3s may require twisted cables for inter-Mac connections such as the Grape & Graphite connection from earlier, but didn't require them when connecting to a switch.

This means that when setting up a LAN for older G3-powered Macs, you can use non-twisted cables - you just need a switch!

Now that this was realized I could actually setup a full 3-Mac LAN on my desk - this was a squeeze as 3x iMac G3s make for a crowded experience, but it wasn't too bad.

My older and younger sisters and I loaded up Age Of Empires (after about an hour of disc images, a wasted CDr and multiple file transfers), and had a few rounds.

Overall the whole setup process took over 2 hours from start to finish, but that was just due to the single-man team and the really long file sharing extension startup times.