[Coco] No Nitr(OS-9) in this coco

[Robert Gault]

Diego Barizo wrote:
> For about a month or so, I didn't use any OS-9 disk, but when earlier 
> this week I went to try a few games, I found that most disks will fail 
> in the boot process, including my custom Nitros-9 disks . This fail 
> after the usual i2xo and then repeats KREL until the screen is filled.
> But when I tried that same disk in a PC running DK's emu, reading the 
> real disk from a 1.2 MB drive, all worked out perfect.
> BASIC disks work also 100% OK on the real coco that refuses to load OS-9.
> In conclusion... the disk is OK because it works with the PC emulator.
> And the drive/controller is OK because it works with any non-OS-9 disk 
> (including games like Ghana Bwana that don't use the standard BASIC format)
> 
> Any clues?
> 
> Diego
> 
> 
OS-9 disks and particularly NitrOS-9 disks are harder to read than Disk 
Basic disks The skip factors are shorter and I/O is more sensitive to 
drive speed.

So if you have these problems, clean the Coco port, controller, and 
drive contacts and check the drive speed for the needed RPM. If an MPI 
is being used, clean its contacts to the Coco port.