Date   : Tue, 07 Apr 2009 12:38:23 +0100
From   : drj@... (David Jones)
Subject: Writing BBC Disc Images on Linux

On 7 Apr 2009, at 12:13, Alex Taylor wrote:

> 2009/4/7 Mike <profpep@...>:
>
>> If writing to a used disc, the data will be over written,
>> leaving a stripe of old data present.
>
> I've often wondered if there's any technical reason why you can't just
> write an identical copy of each track twice when writing a 40-track
> disk with an 80-track drive, rather than double-stepping. This might
> not work so well when creating/copying files, but what about when an
> image is being written to the disk in one go, such as writing a floppy
> image using OmniFlop?

Because it would be difficult to impossible to guarantee that the two  
tracks lined up to an accuracy better than the length of a bit.

drj