Radio Shack TRS-80 Owner's Manual page 98

3
TRS-80
MODEL
ill
DISK
SYSTEM
Entry Conditions
(DE)
=
DCB
(HL)
=
The
extension
to
be added
to
the
file
CALL SPUTEXT
Exit
Conditions
None
$BKSPC
—
17477/X'4445'
This routine positions the
file
record pointer
to the
previous record.
Entry Conditions
(DE)
=
DCB
CALL $BKSPC
Exit
Conditions
z
=
Valid position
nz
=
Invalid position in
file
$REWIND™-
17471/X'443F'
Point
to the
beginning of
the
file.
This
routine positions the
file
pointer
to
the
first
record in the
file.
This
is
useful
when
the
same
file
must
be processed more
than once.
Entry Conditions
(DE)
=
DCB
Exit
Conditions
z
=
Good
file
specification
nz
=
Bad
file
specification
CALL SREWIND
$POSEOF^
17480/X'4448»
Point
to the
end
of
file.
This routine positions the
file
pointer
to the
last
record
in
the
file.
This
may
be used
to
extend
a sequential access
file.
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