[Coco] Issues with NitrOS9 build

[Robert Gault]

Bob Devries wrote:
> Gene,
>
> I'm with you on that one.
>
> I suggest an entry in rules.mak. That would mean just a single line change in
> rules.mak at build time to change the value to 5.25" or 3.5".
>
> E.g. D80TRK=5
> or D80TRK=3
>
> and based on that, the 80 track descriptors should be correctly built, and also
> the format command will select the correct DD.FMT value for LSN0 for 5.25" or
> 3.5" at the discretion of the user/builder.
>
> More thoughts anyone?
>
> Regards, Bob Devries
> Dalby, QLD, Australia
>

If you look in the technical section of OS-9 Level2 you will find that IT.TYP 
bit 0 is defined 0=5" floppy so you would expect 1=3.5" floppy. ITDNS is defined 
as bit0 0=FM 1=MFM, bit1 0=5" 48tpi 1=5" 96tpi. It does not seems to be 
explicitly stated but DD.FMT bit0 0=single sided 1=double sided bit1 is density.

NitrOS-9 has followed this convention and there is no need to change these 
definitions. What would make sense is to decide what format we want an 80-track 
disk to have. It seems reasonable to me that all 40-track disk images be 5.25" 
48tpi disks and all 80-track disk images be 3.5" 135tpi. By convention in the 
current rbf.d file, 48tpi and 135tpi disks are both assigned DNS.STD while 96 
tpi is assigned DNS.DTD.

==================
It should be clear to all, that the initial report of this problem did not 
indicate anything about the actual hardware in use for drives. Please please 
everyone, in future when reporting problems present enough data for the problem 
to be solved. In this case, reporting a problem with DD.FMT and not indicating 
the version of NitrOS-9 in use, whether actual hardware or an emulator was used 
for testing, and what drive hardware was used made it impossible to formulate 
any theories.

Robert