Naked at 30: Osborne 1 stripped to its chips

He ain't heavy. He's my TV typewriter

Mega-floppies with mini-capacity

If you've been around personal computers for a few decades, you'll remember when floppy disks were, well, floppy. The dual 5.25-inch drives in the Osborne 1 used those flexible, black-sleeved disks, the decendants of earlier 8-inch floppies.

That oh-so-convenient port below the drive could house extra floppies (click to enlarge)

The original machine accepted only single-density disks with the amazingly miniscule capacity of 92KB. A double-density, factory-installable optional card, however could just about double that capacity, bringing it up to 182KB.

Trust me, if you want an Osborne 1, you want this optional double-density card (click to enlarge)

According to Oldcomputers.net, the double-density option allowed the floppy drives to also read disks formatted as Xerox 820 single density (82KB), Cromemco single density (80KB), IBM Personal Computer (156KB in the CP/M-86 format), and DEC VT-180 (171KB).

Here are a few views of the full-height 5.25-inch drives in the Osborne 1:

The front of the drive (click to enlarge)

The back (click to enlarge)

The bottom, complete with belt drive (click to enlarge)

Looking into the drive from the top, with floppy inserted (click to enlarge)

As large as these floppy drives now appear, they were compact when compared to the 8-inch drives in my teardown of an S-100 system that I built oh, so many years ago.