HP HP-11C User Manual

Section 5: Programming Basics 93
Unexpected Program Stops
At times a mistake of some kind in your program will stop program
execution. To help you determine why the calculator stopped in the
middle of a program, possible reasons are listed below.
Executing [RTN]. Unless in a subroutine, whenever is
executed in a program, the calculator immediately returns to line
000 and halts.
Encountering the End of Program Memory. When the final
instruction in program memory is not [GTO], (GSB], [RTN] or [R/S],
and is not in a subroutine, a running program will encounter the
end of occupied program memory, transfer immediately to line 000,
and halt.
Pressing Any Key. Pressing any key halts program execution.
The calculator has been designed so that program execution will
not halt in the middle of a digit entry sequence. If you press any
key while a number is being placed in the X-register by a running
program, the entire number will be “written” and the following line
will be executed by the program before the calculator halts.
When a program is halted, you can resume execution by pressing
from the keyboard in Run mode. When you press [R/S], the
program resumes execution where it left off as though it had never
stopped at all.
Error Stops. If the calculator attempts to execute any error-
causing operation (refer to appendix A, Error Conditions) during a
running program, execution immediately halts and the calculator
displays the word Error and a number. To see the line number and
keycode of the error-causing instruction, you can set the HP-11C to
Program mode by first pressing any key to clear the error message,
then pressing [9](P/R].
If an attempted storage register arithmetic operation would result
in overflow in a storage register, the calculator halts and displays
Error 1. The number in the affected storage register remains
unchanged from its previous value. When you clear the error
message, the last number in the display returns.
If the result of a calculation is a number with a magnitude less
than 1.000000000 X 10799, zero will be substituted for that number
and a running program will continue to execute normally. This is
known as an underflow.

HP HP-11C Specifications

General

Brand	HP
Model	HP-11C
Category	Calculator
Language	English