HP -67 Owner's Handbook Manual page 237

Using the I-Register for Indirect Control 233
Press Display
@ 223
260 B0
@
5
Naturally, the most effective use of the I-register as an address for
and is in a program.
Example: The following program uses a loop to place the number
representing its address in storage registers R, through Ry, Rgq
through Rgg, and R, through Rg. During each iteration through the
loop, program execution pauses to show the current value of I.
When I reaches zero, executionis finally transferred out of the loop
by the £ instruction and the program stops.
To key in the program:
Slide the W/PRGM-RUN switch weram [[IIMRUN to W/PRGM.
Press Display
o
o
@
8 003 31 42
0 Program initialized.
2
5
Q (s11
8 (e] 1 Current value in I stored
Q) (rer in storage register
@ addressed by (@ .
o Pause to display current
value of 1.
012 31 33 Subtract one from value
in I-register.
1 013 22 01] If I#0, execute loop
again.