I remember a device that had both serial and ADB on it designed for iMacs. The name escapes me, but I think it was USB. It used to sit under the iMac and provided a bunch of legacy ports. As long as you could accommodate its awkward (for a G4 tower) shape, it may be an option. I seem to recall these being advertised in Mac Warehouse and similar catalogs around 1998-1999 when the iMac first came out. Not sure if it had SCSI.

Click to expand...

Sounds like the iDock that Bunsen mentioned. I found some reviews of them. They seemed to be hit-and-miss in the reliability stakes.

If you're open to purchasing another machine, the blue and white G3 towers actually have on-board ADB, so all you'd need is the serial card.

Click to expand...

Funny thing is, I saw an ad for one of these but was in two minds as to whether I should pick it up. But seeing as it has ADB I'm gonna go and get it. I'd probably pay almost as much for a used iMate with shipping and I'm getting a full machine with keyboard, mouse and monitor. Plus I'll be able to install OS X Server 1.x onto it (the 1.2v3 disc needed for the Gigabit Ethernet is impossible to find).

IIRC, these (and possibly the Keyspan) are the only solutions that work with Localtalk and MIDI.

Click to expand...

I know the Keyspan definitely works with MIDI. It was one of their main selling points. Not sure about Localtalk as I've never used it.