Re: DOS 3.3 File Manager calls - stomping on Track 0, sector 0

["mmphosis" <markstock@mail.com>]

schmidtd wrote:
> josephoswaldgg@hotmail.com wrote:
> Does anyone know how to trap the I/O errors that happen when using this interface?  Right now, it dumps me back into BASIC.

Yes.  Look at what "jmp error" is doing in the code.

I suspect that calling the File Manager routines might be a bit tricky
and might have a bug or two.  Perhaps, this code has a bug or two as
well.  Seems that it might be doing an extra call to RWTS to write some
data to track 0 sector 0.  Perhaps, some initialization or termination
routine needs to be called before calling the File Manager routine.

In the past, I used the RWTS routines directly.  I think I checked for
the carry flag being set which indicated an error.  The error code is
returned in the parameter list for RWTS.  The error code might also be
stored in location $48 in the zero page which conflicts with other
routines that might use this location -- a cause of some bugs.