Commodore 16 - Page 72

EXAMPLES:
SSHAPE "VARIABLES",
0,
GSHAPE "VARIABLES".,,!
Saves
screen
area from me upper
left corner
lo
where
me cursor is
positioned under
me name
VARIABLES.
Displays
VARIABLES shape with
background
and foreground colours
reversed, with
me loo
left ol
me
snope
positioned at the cursor
STOP
STOP
This
statement halls
the program. A message. BREAK
IN LINE
*
where
the # is the line number containing
me STOP The program can
be
re-slarted
at the statement following
STOP It you use the CONT
command. The STOP
statement is usually
used while debugging
a
pfogram.
SYS
SYS address
The
word SYS is
followed
by a
decimal number or numeric variable
m
the range
to 65535. The program begins executing
me
machine
language
p'ogram stantng
at thai memory location. This is similar
lo
the
USR
function,
but
does
not
pass a
parameter.
See the
Programmer's Reference
Guide tor information
about
machine
language programs.
140
TRAP
TRAP (lineal
When
turned on TRAP intercepts all error conditions (including
Ihe
ntm/STOP
key) except "UNDEF'D STATEMENT ERROR" Intneeveni
of any execution error, tne error
flag is set, and execution is transferred
lo the line number named in
the
TRAP
statement. The
line
number in
which Ihe error occurred
can be tound by
using
me system variable
EL.
The specific error condition is contained
In system
variable
ER. The
string function
ERRSfER) gives the error message corresponding
to any
error condition
ER,
NOTE: An error
m a
TRAP
routine cannot be trapped The
RESUME
statement can
be used lo resume
execution.
TRAP with no line*
argument
turns oft error TRAPping.
TRON
TRON
TRON is
used
in program debugging
This statement begins trace
mode When
you
are in trace mode,
as each statement executes, the
line number of Ihat stalement is printed
TRQFF
TROFF
This
statement
turns
trace
mode
off.
141