That's a MiniScribe stepper motor hard drive - they tend to get a bad rap but make a set of sounds like none other.
If you can't get HD SC Setup to recognize it, try Lido instead - I had a couple of those drives that I'd all but given up on. Lido worked when everything else failed.
Wow. Talk about a fancy setup! Hate to think about how much all that would have cost back then..
Any time I see stuff like this I wish I could see the reaction on some modern Apple employee's face to 1) the fact that all that stuff existed back then and 2) that someone is actually using it for anything practical. There's got to be at least a few people who don't have a clue.
I am guessing this is some form of testing tool. Anyone have any idea what it might be? It's stuck in shipping so who knows if/when I'll get it. It's an Apple Development Team "black box" The person I got it from had no idea what it was either so no clues there.
I would think the only point of throwing an actual memory slot on there would be the possibly of using existing memory sticks and replacements if failure should occur. Any time a component is soldered down it becomes significantly more complicated to replace if it fails.