Program Command List - Radio Shack TRS-80 26-3650 Service Manual

6.
PROGRAM COMMAND
LIST
Classification
Command
Name
Format
Function
Input
statement
INPUT INPUT
variable string Causes data to be entered from
the key-
board during execution
of a program.
The program
execution
is
stopped
until
after
the end of
input.
KEY
Character
variable
=
KEY
Reads
a
character entered during
execu-
tion of a
program and
assigns
it
to a
character variable.
Since the program
is
not stopped by
this
command,
nothing
is
assigned to the
character
variable
if
no key
entry
is
made.
Output
statement
PRINT PRINT
output
control
function
J
'
I
output element J
'
I
. . .
Outputs
the designated output
element.
CSR
CSR
n<j
;
l
(O^n
<^^)
Displays
from
the designated nth
position.
Branching
GOTO
GOTO I""
6
™)
Invariable
1
Causes control to
jump
to the designated
line
number.
IF...
TTHENl
IF
comparison
expression
TthEN
line
no.
1
\
;
command/
Causes control to
jump
to the
line
number
following
THEN,
or executes
the
command
following ";",
if
the
result
of the comparison
is
true.
Causes
control to proceed to the next
line
number
if
the
result
of the com-
parison
is
false.
GOSUB
GOSUB
(
iinen °\
[variable!
Calls
out
the subroutine of the
desig-
nated
line
number
for execution. After
the subroutine
is
executed, control
returns
to the
GOSUB
statement by the
RETURN
statement
to
proceed to
the
command
following that statement.
RETURN RETURN
Signifies the
end
of
a
subroutine;
returns control to the
command/statement/
function next to the
GOSUB
statement.
Looping
FOR FORv
=
e1TOe2[STEPe3]
*v denotes
a
numerical
variable,
and
el,
e2 and e3
represent
a
numerical ex-
pression respectively.
Declares the beginning of a loop
in
which
numerical value
v
changes from
initial
value el to terminal value e2
in
increments of
e3.
The
loop
is
repeated
"e2-e1
,
."
_
+1
times
ej
between
the
FOR
and
NEXT
statements.
If
the increment e3
is
omitted, e3
is
regarded
as
"1".
NEXT NEXT
v
Signifies
the
end
of
a
FOR
loop.
If
the
result of v plus
e3
is
equal to or
smaller than
e2,
the loop
is
repeated
again.
If it is
greater than
e2, control
proceeds to the
line
next to
the
NEXT
statement.
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