[Coco] Fixing OS-9 format for those that "roll their own"

[Robert Gault]

Gene Heskett wrote:
><snip>
>
> I am not convinced the numsides checking is correct for a hard drive.
>
> Why? We access hard drives, or at least the superscsi drivers I use do, by
> addressing the LSN, and the drive is smart enough to figure out the
> side/platter that LSN is on.  So our descriptors should be considered
> complete when they simply say its a hard drive.
>
> Do we have drivers that do care?  That I don't know.  Discuss?
>
> --

OS-9 probably doesn't care and the driver for a hard drive should be able to 
query the hard drive itself for the configuration. The problem is present with 
emulators and utility programs that generally have to cope with nothing more 
than a file name to determine the type of disk.
After guessing the type of disk based on the file name, the descriptor or LSN0 
may need to inform the driver of all low level parameters as the disk can't talk 
back to the driver (unless there is a detailed header.)

I'm pretty sure my message resulted from answering a person trying to write a PC 
utility that could read/write to disk images. The program needed to determine 
the structure of the disk via the information in LSN0 (assuming OS-9) and DD.FMT 
was providing confusing information.
So..., rbf.d provides a detailed description of IT.TYP but this was not getting 
through to the format command source code.