If this were circa 2004-2005, I'm curious as to what it would have been using for a processor: Intel Atom (which had some Kernel Extensions in Leopard, enabling a generation of Dell Mini 9/10 Hackintoshes, IIRC), ARM, Core or maybe even G4?
You're assuming that this prototype was fully functional. It might've been a design-model, intended only to demonstrate the look, feel, weight, etc. It might not have any electronics in it.
Given the size, it might also have been a hacked-up iBook. Take an iBook, remove the keyboard, attach the screen to the lower case and add a touch screen (a-la the ModBook), and now you've got a platform where you can run UI experiments. If they did that, then it would've been a G3 or G4.
I personally doubt that this prototype was ever seriously intended to be sold as a product. I think it was just an experiment to try out different design aspects.
YES, darnit, I know iOS is OS X-based.
In the early days of the iPhone, they even called it "OS X".
I suppose, if you would map out the family tree here, you'd end up with something along the lines of:
BSD, Mach, and a few other techs --> Darwin
... + many system frameworks --> OS X
... ... + Mac-like UI frameworks --> Mac OS X
... ... + touch-based UI frameworks --> iOS
I wonder if anybody actually has one of these?
I would be shocked if more than one or two were ever built. And it would surprise me greatly if they could run any software aside from, perhaps, some basic UI-test applications.
I was thinking this too. I would love an iPad that ran full on OSX.
You probably wouldn't like it. Mac OS X is really designed around a pointer/keyboard paradigm. It would be painful on a touch-only platform. While you could probably manipulate the Finder and many system dialogs, I think most apps would have inaccessible features.
Although it's not an exact match, go install a Magic Trackpad on a Mac, and disconnect all your other input devices. I don't think you'd enjoy working with the result.