Date   : Wed, 16 May 2012 18:53:30 +0100
From   : walker_matt@... (Matt Walker)
Subject: Basics - saving files onto disk

> Hi,
>
> I have a simple question: How do I save a file onto a 3.5" (dual density)
> floppy? I tried using 'SAVE "filename"' but I got the message 'Sector not
> found at 00/00' - is it trying to find a tape?
>
> My BBC Micro has the Watford chip which allows me to use dual density.
>
> Thanks for your help.
>
> Marc

If you're using the 3.5" drive from a PC, it may be set to Drive 1 & 3, try 
typing *DRIVE1 before SAVE"filename"
You can change the drive to appear as drives 0 & 2, this is usually on a 
jumper or 2 pads that can be bridged with solder.
And as Mark said, make sure this disc is formatted.