Date   : Fri, 14 Oct 2005 07:35:13 +0200
From   : Eelco Huininga <eelco@...>
Subject: Re: 3.5" Floppy For A Master

Jonathan Graham Harston wrote:
>>Message-ID: <434AAC92.80204@...>
> 
>  
> Eelco Huininga <eelco@...> wrote:
> 
>>Is that a DD or HD drive?
> 
>  
> In practice there's no such thing.
>  
> A 3.5" drive detects the disk type by noticing the second hold on
> a HD disk. That's one of the reasons you shouldn't fake a HD disk
> to DD by covering the hole, 'cos the drive will then use the wrong
> write current to write to the disk and ruin it.
>  

Hmmm I always thought HD drives could be switched between the DD and HD 
modes by an extra input signal (pin 2 I think). So if drives auto-detect 
the density of floppydisks, what is this signal for then?

Cheers,
Eelco