classics I threw away or sold ... foolishly

No, it's just a sort-of ordinary, though thick floppy drive. The one I had contained two floppy drives, and had a blue power button. I think I remember the drives being single sided. The floppy drives attached to the system unit over HP-IB, and the cable I had connected at a strange angle and was barely long enough to stack the system as depicted in the picture you linked. There were several expansion slots in the back of the system unit, and there was space in the top for a thermal printer, though I never had any cards or the printer. I got the thing from my grandmother, who had two at one time and the second one had the printer and all the software, but she had pitched it before I thought to acquire the other one. It was too bad, because the other one had a chess game that could use the touch screen that was tons of fun to play as a kid. However, the keyboard on it was one of the worst I ever experienced. The keycaps were all rectangular, and the kickstand put it up at such a steep angle that if you didn't make sure to press each key perfectly straight down, you'd accidentally push the key toward the back of the keyboard a bit and it'd get pinched and not go down far enough to register a keypress. The whole system isn't quite 100% MS-DOS compatible, so you can't boot it from any old DOS boot disk. I never had the original disks once it was actually "mine". Anyway, fun times. -Ben