I decided to pull out and take apart the Mac Plus Hyperdrive 20 machine to see whats inside, This is the machine i picked up from the rack full of compacts at the Dayton Hamvention

The back said HyperDrive 2000, so i was like oh boy....

I took the back off, and there was no drive inside, awww..... BUT not to despair. They left the board in there. and its the HyperDrive 2000 board. The machine did NOT boot, it powered on to jailbars, no beep. So no idea whats going on.

So even though the drive is missing, at least its a glorified RAM upgrade + accelerator.