[Coco] 3.5" Drive Variable in the NitrOS-9 Module Header

[Steven Hirsch]

On Sun, 27 Jan 2013, David Ladd wrote:

>> Also, to use a 3.5" 1.44m disk as 720k, you could cover the "HD" id hole
>> on the disk and the drive would recognize the disk as 720k. The hole was
>> opposite of the write protect slider. I used the old write protect stickers
>> from 5.25" disks for this. If the disk had been "factory formatted" for
>> IBM, most times you needed to use a bulk eraser to clear the disk because
>> the drive eraser wasn't strong enough to erase those "factory formatted"
>> disks.
>>
>
> Bill, good thing you brought that up.  I forgot to say anything about using
> 1.44MB disks as 720K disks.

I wouldn't suggest using 1.44M media for 720k storage.  This has been 
discussed to death on various mailing lists and fora, but essentially the 
magnetic coating on HD 1.44M media has a higher coercivity threshold than 
the older DD 720k diskettes.  A drive writing at DD cannot fully saturate 
the magnetic domains.  Even if the diskette appears to write without 
errors and possibly read back immediately after, your prospects for 
long-term data reliability are poor.

This also applies to 1.2M 5.25" media, FWIW.

Steve


--