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INPUT/OUTPUT FUNCTIONS
25.2 -- Device Dependent I/O Functions
physical sector.
c
=
1 if an error occurred
The
remainder
of
indeterminate.
<.
EREAD
on
1
y
>.
the
CC
is
The
A
register is indeterminate ..
The X
registe'r is unchanged.
The
B
register
contains the return
status returned
in
the first byte
of
the parameter packet.
The
first
byte
of
the
parameter
packet
contains
the
diSkette
controller
error ($31-$39>'
Section
28.1 has a
complete
desc1'iption
oOP
the diskette controller er1'ors.
The
contents
of the
128
byte sector
bUrrel'
are
indeterminate.
25.2.6 Physical sector output -- .OWRIT, .EWRIT
The . DWRIT and. EWRIT functions
are
both used to write
a
single
physical
sector
to
the
diskette
from
a
specified
buffer.
For multiple physical sector
output
the
functions
described
in
section
25.2.8
should
be
used.
The. DWRIT
function will only
return
to
the
calling
program
if
no
diskette
controller
errors
are
detected
during the write
attempt.
The. EWRIT function}
on the other hand, will return
to the calling program whether an error occurred or not.
The
.EWRIT
function
will
return
the
error
status
that
was
detected
by
the diskette controller.
If
an
error
occurred,
procedure described in section
attempted.
In
addition, the
those functions regarding the
apply to the .
DWRIT
and.
EWRIT
the
same
type
of
recovery
25.2.5
(.DREAD,
.EREAD)
was
~ame
precautions described for
restoring
of
the
read
head
funtti ons.
ENTRY PARAMETERS:
EXIT CONDITIONS:
Same
as
for . DREAD and
.EREADi
however,
the sector bufrer-
must
contain
the
128
bytes
that are to be written to
the diskette.
Same as for . DREAD and
.EREAD;
however,
the the contents of the sector buffer
are unchanged
aft~r
returning to
the
calling program.
Page
25-11
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