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

[Bruce W. Calkins]

----- Original Message ----- 

From: "Kip Koon" <

> NitrOS-9 Developers,
>
> I have been giving some serious thought to the recent discussions

> about when to use a track density of 48 tpi or 96 tpi.  Here's my

> thoughts on the matter.  Create a new bit in the Drive Descriptor

> which is called '3.5" Drive Track Density' and this is how it would

> work.

>
> Kip



========================



Short answer: it is a hardware issue.  You basically need to build a new 
floppy controller to use 5.25" 1.2M & 3.5" 1.44M disk drives with 5.25" 1.2M 
& 3.5" 1.44M media.



5.25" 1.2M & 3.5" 1.44M disk drive require 500 kbs input vs. the lower 
capacity drives 250 kbs.  There is/was a hack to modify the 26-3022 12 volt 
controllers to the higher speed.  But there is no way to convert later CoCo 
floppy controllers.



Using 3.5" 1.44M disks at 720k in a 1.44M drive results in unstable 
recordings, BTDT.  Using 720k disks in a 1.44M drive works OK.  I have a few 
720k disks and had few issues with them when I was running them.  I had a 
few 720k drives and they all were problematic and not compatible with the 
1.44M drives.



Bruce W.