USUS library

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Oct 29 17:42:19 1999

John wrote:
> He also mentioned he has source code on 8 inch disks from an
> Ohio Scientific, Inc. machine. He thought hed have more trouble
> finding a way to read those because of its scheme of using an
> 6820 parallel port controller and a 6850 serial port controller
> to access floppies. Is that true? Should the normal scheme for
> connecting a Shugart-y drive to an old AT-era WD controller
> work to read these old disks?

He's right. Ohio Scientific used a UART as a disk controller. I haven't
looked at the schematics, so I'm not sure what method they used to avoid
long runs without flux transitions; maybe they really could tolerate nine
zeros (a start bit and eight data bits) between ones (stop bits).

Anyhow, the only way I know to read those disks is to use the actual
Ohio Scientific hardware. If that couldn't be done, I think I could hack
together something with a Scenix microcontroller.

Eric
Received on Fri Oct 29 1999 - 17:42:19 BST