[Coco] OS-9 RBF - accessing past what LSN0 says?

[Allen Huffman]

I have a 128MB EZ135 disk that I used with RGB-DOS/OS-9.  I put 255 RGB-DOS drives on it at the end, and used the rest of the space for OS-9 (about 50MB).

The OS-9 section has an LSN0 that says 0313FE (201,726) sectors, and beyond that is the RGB-DOS portion.

If I use dEd, or BASIC09, and try to get past sector 201,726, it won’t let me. In years past, I have gotten around this by modifying LSN0 to something larger, and then I can. That’s what I resorted to doing tonight.

How do utilities like RSDOS and PCDOS work when you put in a disk without an LSN0? I expect the driver itself does not care (if it’s like OSK/OS-9000).

Thanks for any shedding of light you might be able to do…

		— Allen