[Coco] NitrOS9 build errors

[Theodore (Alex) Evans]

On 01/20/2014 03:57 PM, Gene Heskett wrote:

> No, because the settings for an 80 track, 96 tpi 5.25 disk ARE different
> than for a 80 track, 135 tpi 3.5" disk even if both are an identical 720k
> in capacity.

Yes, the way that has been arbitrarily decided, they are different.

> In the former case the disk is _double_ track density, and the bit in
> offset $10 of LSN0 is set accordingly.  In the latter case, that 135 is the
> normal track density, in fact the only known track density for 3.5" disks,
> so that bit in offset $10 of LSN0 is not set.
>
> So you cannot and must not use a common format for both disks even if the
> capacity is identical.

This is exactly why a 720k 3.5" floppy should be set as 96tpi in the 
descriptor even though it is a 135tpi disk.  If there were 160 track 
3.5" floppies, there would be some reason, but I have never heard of 
such things.  Since I used a common format when I started using 3.5" 
floppies on my CoCo 3 (I used the 80 track descriptor that shipped with 
level 2 at that time) one certainly can.  You may think that it is a bad 
idea, but it is certainly possible to do.