Sharp MZ-80B boot disk

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Thu Dec 19 13:13:00 2002

> > I meant to say that on the Apple ][ a malfunctiong disk controller could
> > override write protect, even on a non-malfunctioning drive. THAT is the
> > special unique feature.

On Wed, 18 Dec 2002, Sellam Ismail wrote:
> I once had a drive that was over-riding the write protect mechanism on the
> floppy because the write-protect sensor failed in some manner.

Yep. many things can do that, even loose mounting screws for the switch.

Had one client who used clear scotch tape for write protect. He INSISTED
that something else must be wrong, since that had always worked right on
his previous machine.

I remember when Centech first came out with cheap colored 5.25" diskettes,
some drives couldn't use them due to a photocell to detect disk presence
that was getting some light through the disk!


> I think I've only ever once come across a bad disk controller on the
> Apple.

Although I did VERY little with Apple stuff (you will recall that I only
had two Apples when I closed my office), I encountered berserk controllers
wiping disks three times. Two were OEM, one was generic after-market.
One of them was a client, who when he found that he couldn't boot, had
assigned his secretary to systematically try every disk in the file
cabinet. THAT was why I expressed the caveat of "never put you LAST boot
disk into the machine".
Received on Thu Dec 19 2002 - 13:13:00 GMT