Date   : Sat, 18 Nov 2006 04:58:57 -0600
From   : julesrichardsonuk@... (Jules Richardson)
Subject: Unusual piece of equipment available.

Jonathan Graham Harston wrote:
>> Message-ID: <45492360.7020500@...>
>  
> Richard Gellman <splodge@...> wrote:
>> What we have on offer here is a floppy disc drive cable (of the BBC
>> Micro variety) with one edge connector on the end, but fitted with a
>> switch to convert an 80-track drive into a 40/80 switchable.
>  
> How? There are no connections on the disk drive connector to
> control the number of tracks or the stepping rate. Some disk
> drives have links or pads on them that a switch can be wired to,
> but that is on the PCB, not on the drive connector.

I seem to recall that there are a couple of pins where the function varies 
between drives, though, and for some machine / drive setups they aren't needed 
at all. It may be that the beeb doesn't use all of the lines - so that there's 
one free which could be used to control the number of tracks.

Of course you need knowledge of the floppy drive being used and have to hack 
it, but I suppose it could be done *for a specific drive*

(having the track count selectable via software on the beeb would be kinda 
cool, but I'm not sure how much flexibility is available in the beeb's FDC 
circuitry)

cheers

Jules