[Coco] Technical OS9 Q.

[Bob Devries]

I'm wanting to add a directory entry into a OS-9 .dsk or .vhd file on the 
PC. Remember this is to run on the PC, and is programmed in PC C, not under 
OS-9.

I've worked out that I need to first step through the directory, looking for 
a deleted file slot (starts with '\0').
If that fails, I need to add the new file to the end of the directory, OK, 
so that is no problem unless.....

What if the directory allocation is fully utilised? That is, all the sectors 
originally allocated are used? I would need to allocate another block of 
sectors, but how will I know how many to allocate? Under OS-9, the create 
file routine would use IT.SAS from the device descriptor, but this value is 
not available to me.

How should I proceed? Any clues? Suggestions?
--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/