[Coco] OS-9 and RS-DOS disk structures

[Allen Huffman]

On Dec 31, 2014, at 11:43 AM, Allen Huffman <alsplace at pobox.com> wrote:

>> So, let's say you just want to copy real double-sided OS-9 disks to second disk. If that is the goal, just use BACKUP from Disk Basic or backup from OS-9.
>> Disk Basic with 0=front and 2=back Drive A, 1=front 3=back Drive B
>> You would just
>> 10 BACKUP0TO1
>> 20 BACKUP2TO3
> 
> This actually solves my problem. I am doing this on a real CoCo using the CoCoSDC floppy drive emulator. The CoCoSDC emulates the WD1774 floppy controller, and can act like physical DRIVE 0 or DRIVE 1. It redirects all of the WD1774 disk I/O to sectors inside of a .DSK image on the SD card. You can turn off either drive so accesses then go to the real floppy controller.

Nevermind. False alarm. It appears SDC-DOS may be intercepting the drive numbers. It fails to honor POKEing those values when using the .DSK images.

However, CoCoSDC also comes with stock DECB 1.1 in another bank, so I can type:

RUN @1

And poof! I'm now in normal BASIC with no SDC commands. If I mount my two images from SDC-DOS, then RUN at 1 to switch to DECB 1.1, I can do the pokes and it sorta works. At least, I am seeing DRIVE 0 and DRIVE 1 as I expect, and 2 and 3 are "something" else... DSKINI fails, but someone posted earlier than CoCoSDC doesn't expand on the format command or something.

I was able to DSKO$ to these "back side" drives and it gave no error, but trashed all the directories.

I'm getting closer, at least, but I'm starting to feel what I want to do I can't actually do from BASIC. I may be booting OS-9 sooner than I had planned ;-)

		-- Allen