HP HP-11C

Section 9: The Index Register 133
Now run the program by pressing [f](A].
Keystrokes Display
2.0000
4.0000
4.0000
16.0000
50.0000
2,500.0000
When the calculator
begins executing, it first
pauses to display the
number to be squared,
then pauses to display the
square of the number.
When the loop counter
increments beyond 50, the
program halts.
Here is what happens when you run the above program.
1. Under label [A], the number 2.05002 is stored in the I-register
as the loop control value:
nnnnn XXX vy
(0000)2 050 02
Current Counter Test Increment
Value Value Value
2. Underlabel 1, the following sequence occurs:
After 2 and 4 (the square of 2) are displayed, the current
counter value in R;, 00002 (nnnnn), is incremented by the
increment value 02 (yy). The new number in R; is 4.05002,
which is interpreted by your calculator as:
nnnnn XXX Yy
(0000)4 050 02
Current Counter Test increment
Value Value Value
The new counter value is then compared to the test value 050
(xxx). As the counter value has not exceeded the test value,
the calculator proceeds to the next line, 1, and the
process is repeated with the new number.