On the back of this question, it got me thinking that it has always been that ProDOS would only support a ",D1" and ",D2" on a slot, i.e. slot 6 would have two addressible drives. With my 20MB Sider hard disk back in the day, I had only two partitions there as well which mapped /HARD1
to ,S7,D1
and /HARD2
to ,S7,D2
.
Ever since I've been playing with emulators that supported hard disks, I did notice that you can have multiple volumes mounted on slot 7. Though ProDOS doesn't seem to allow you to do (say) ,S7,D6
, you are able to mount a /HARD6
(to keep with my naming scheme from before).
How did ProDOS allow this behavior? And in the spirit of the question I linked to at the start of this, why wouldn't you be able to mount more than one volume on a floppy controller? The thing which makes it a touch puzzling is that SmartPort devices apparently could map themselves to other slots as needed and also devices such as a CFFA 3000 allow for mapping volumes to multiple slots and exceeding ,D3
conventions.