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Commodore Plus 4 - Page 325

Commodore Plus 4
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The
Operating
System
313
$FFD5
LOADS?
Registers
Altered:
.A,
.X,
.Y
Loads
a
file
into
memory
or
verifies
a
file
against
memory.
For
a
relocated
load,
.X
contains
the
low
byte
of
the
load
address
and
.Y
contains
the
high
byte.
After
storing
this
load
address,
the
routine
vectors
through
$032E-$032F.
For
a
load,
.A
should
be
$00.
For
a
verify
operation
in
which
the
designated
memory
is
compared
with
the
file
but
not
changed,
.A
should
be
$01
(or
another
nonzero
value).
The
call
to
this
subroutine
must
be
preceded
by
calls
to
SETLFS
($FFBA)
and
SETNAM
($FFBD).
If
the
secondary
address
sent
with
SETLFS
is
$00,
then
the
load
is
relocated
to
the
address given
in
.X
and
.Y
and
the
first
2
bytes
of
the
file
are
ignored;
otherwise
the
first
2
bytes
of
the
file
specify
the
load
address.
In
any
case,
.X
returns
with
the
low
byte
of
the
last
address
loaded
(+1)
and
.Y with
the
high
byte
of
the
last
address
loaded
(+1).
For
a
verify,
the
status
byte
is
$00
for
a
valid
compare
and
$10
when
a
difference
is
found.
If
an
error
occurs,
the
message
flag
(see
SETMSG
$FF90)
is
consulted
to
determine
what
message
(if
any)
to
output.
The
carry
is
returned
set,
and
.A
contains
the
error
number.
The
possible
errors
are
as
follows:
$00
=
The
routine
was
terminated
by
the
STOP
key.
$04
=
The
specified
file
name
is
not
found
on
the
specified
device.
$05
=
The
specified
device
is
not
present.
$08
=
The
file
name
was
missing.
$09
=
The
specified
device
is
illegal
for
this
purpose.
The
system
I/O
status
byte
may
also
be
checked
for
errors.
It
is
read
using
READSS
($FFB7).
$FFD8
SAVESP
^
Registers
Altered:
.A,
.X,
.Y
Saves
memory
into
a
file.
The
address
to
start
the
save
must
be
stored
on
zero
page,
low
byte
followed
by
high
byte.
This
zero
page
location
must
then
be
placed
in
.A.
The
low
byte
of
the
address
to
stop
the
save
(plus
1)
must
be
placed
in
.X
and
the
high
byte
in
.Y.
After
these
addresses
are
stored,
the
routine
vectors
through
$O33O-$O331.
The
call
to
this
subroutine
must
be
preceded
by
calls
to
SETLFS
($FFBA)
and
SETNAM
($FFBD).
If
an
error occurs,
the
message
flag
(see
SETMGS,
$FF90)
is
consulted
to
determine
what
message
(if
any)
to
output.
The
carry
is
returned
set,
and
.A
contains
the
error
number.
The
possible
errors are
as
follows:

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