[Coco] continuing to eliminate errors in the nitros9 build

[Bob Devries]

OK, Gene,

I have changed the SAS to 4 on my build, and it still builds without error 
248 on the single-sided tano and d64 disks.
So the new instructions are:

In file /nitros9/level1/d64/makefile

under $(DSK180K_1):

change:

$(OS9FORMAT_SS40) -e -dr -q $@ -n"NitrOS-9/6809/Dragon Level 1 Disk1"

to:

$(OS9FORMAT_SS40) -sa=4 -e -dr -q $@ -n"NitrOS-9/6809/Dragon Level 1 Disk1"

Regards, Bob Devries
Dalby, QLD, Australia