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OTHER SYSTEM FUNCTIONS
EXIT CONDITIONS:
27.4 -- Diskette File Functions
SBE
must
contain
the ending address of
the
secto~
buffer.
If
the
secto~
--buffer
is
larg~~
than
one
sect~r,
only
the
first
128
bytes
will
be
used.
A
is
indeterminate.
B
contains the retuT'n
status.
The
return
statuses are taken from
the
set
of
codes
defined
for
the
device
indep endent I/O
runc t
ions.
Only
the
system
symbols
are
given
here for
those
return
statuses.
The
exact
values
can
be
found
from the MDOS
eq,uate
fi Ie,
section
25.3.
i.
I,
or
section
28.3.
The
following return
statuses
~re
defined:
B
=
0
indicates
that
no
errors
occurred
(norma
1
return).
B
=
I$RIB
indicates that the file had an
existing Retrieval Information
Block
that was invalid (see section
24.2>.
B = I$RANG
indicates
that
the
maximum
referenced
logical
sector
number
specified
in
bytes
1
and
2
does not
belong to the fi Ie.
That is,
the LSN
specified
is gT'eater than the number
of sectors belonging
<allocated)
to
the file.
B
=
I$IDEN
indicates that an invalid
DEN
was specified.
B
=
I$OEAL
indicates that an attempt
was
made
to
deallocate
all of a file's
space (bytes 1 and 2 set
to
$FFFF),
but
the directory entry for the file
was not flagged as deleted.
X
is
unchanged.
C = 0
if
no errors occurred (B = 0),
The
remainder of
CC
is indeterminate.
C
=
1
if an error occurred (B not zero).
The remainder of CC is indeterminate.
The DFT is only changed if the all
of
a
file's
space
was to be deallocated.
In that case, RIB
will
contain
the
Page
27-29
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