Date   : Thu, 21 Nov 1996 13:52:54 +0000 (GMT)
From   : Tom Seddon <n5013784%mere19@...>
Subject: More filing-system stuff

Work on my filing system progresses (slowly), and I still need some more 
answers! If anyone with a real Beeb would be able to help I'd be most 
grateful.

1. OSGBPB can be called to read bytes from a file at a specific pointer 
setting. If this pointer setting is set past the end of a file, what happens:

1.1 when the file is read-only?
1.2 when the file is writeable as well?
1.3 when the file is write-only?

What I'm getting at is: is an error given? Is the file extended? What is 
returned? The AUG says C should be set on error but I like to be 
accurate, so if there are any other side effects I'd like to know.

2. When running a file thus:

	*FRED
   if you specify a directory, eg:

	*$.FRED

   does the library drive get checked as well?

3. What happens if the library drive has no disk in it, and you try to 
run a file whic hisn't on the current drive? Does the no-disk-in-drive 
get checked or does the computer just stop?

4. When writing to an read-only open file via OSGBPB or OSBPUT, what 
happens? (BRK message? C flag set?)

5. When reading from a write-only file via OSGBPB or OSBGET, what 
happens? (BRK message? C flag set?)

Once again, any help much appreciated.

--Tom
T.W.Seddon@...