Radio Shack TRS-80 26-3650

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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