Program Command List - Radio Shack TRS-80 Service Manual

6. PROGRAM COMMAND LIST
C.. ssification
Command
Format Function
Name
Input
INPUT INPUT variable string Causes data to be entered from the key-
statement 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 duringexecu-
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 PRINT
PR INT output control
Outputs the designated output element.
statement
function
f}
output
ele~nt
({} ..
.J
CSR
CSR n{} (0
~
n
~
11)
Displays from the designated nth
position.
-
Branching
GOTO
GOTO {line no. }
Causes control to jump to the designated
variable line number.
IF ... IF comparison expression Causes control to jump to the line
{TH;EN}. ..
{THEN line no.
J
number following THEN, or executes
; command the command following" ;", if the
result of the comparison is true.
Causes control
10
proceed to the next
line number if the result of the com-
parison is false.
GOSUB
GOSUB
~inenoJ
Calls out the subroutine of the
desig-
variable nated line number for execution. After
the subroutine is executed, control
returns to the GOSUB statement by the
RETU RN 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 FOR v
=
e1 TO e2 [STEP e31
Declares the beginning of a loop in
*v denotes a numerical
which numerical value v changes from
variable, and e1, e2 and e3
initial value elto terminal value e2 in
represent a numerical ex-
increments of e3. The loop is repeated
pression respectively.
"e2 - e1
"
- - + 1 times
e3
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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