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LOAD COMMAND
18. 1 -- Use
Caution
must
be
exercised
in
starting
exeCU~lon
of
programs loaded in this
manner.
Since
the
stack
pointer
contains the address of the last loaded program locationl use
of the debug monitor commands
"iP"
or ";N" will
cause
seven
locations
of
the
program
to be destroyed.
This
ma~
alter
program data or instructions.
It
is
recommended
that
the
s t a
c
k
poi
n t er fir s t
b
e chan g e d v
i
a the
It
is''
comma n d
i
t hat the
"nnnn;G" command be used to initiate execution; or that
area
for the stack be
provid~d
at the end or the program.
The LOAD
co~mand/s
"G" option can be used in addition to
the
"un
option to give control
to
the
program
immediately
after
it
has been loaded:
LOAD TESTPRDGjUG
The "M6800 EXORciser II User's Gu.:ide" should be consulted for
a complete discussion of the User Memory Map.
If the
"un
option is
used
(~ith
or
without
the
"G"
option),
the
SWI
vector
will
be restored to its original
value that points baCK to the debug monitor.
Thus,
programs
loaded
with
the
nu"
option
cannot
use the resident MDOS
runc tions.
18.1.4 /'rIDOS command line initialization
The
Other
Option
«str»
is
used
while
testing
c ommand-i nterprete'T'-l oadab 1 e programs (sec t i on 18.
1.
1).
Sue h
prog~ams
usually obtain parameters via
the
initial
command
line that activated the program.
When testing such programs,
however, the command line buffer
will
contain
the
command
line that- invoked the LOAD command.
Thus,
the «str:»
option
is used to allow testing of the loaded program as if
it
had
been
invo-ked
from the command line directly, simulating its
execution-time
environment.
The
quantity
<str>
will
be
place-d
into
the
MDOS
command line buffer.
The command line
buffer pointer, CBUFP$ (Chapter
24),
will
be
adjusted
to
point
to a null character which precedes the string (a valid
terminator
for
the
. PFNAM
function;
Chapter
27>'
Any
displayable characters, except the right parenthesis
It)",
can
be
included
in
the
string
<str>.
The
string
will
be
terminated with a carriage return after it is placed into the
command line buffer.
Thus,
the use of the null string
U( )11,
will
cause
a
single
carriage return to be placed into the
buffer.
The «str»
option can be used
with
any
of
the
Main
Options;
however,
it only makes sense when no Main Option is
used (command-interpreter-loadable programs).
Page
18-07
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