HP -67 Owner's Handbook Manual page 300

296 Card Reader Operations
To run the program to find the area of a circle with a radius of 15
centimeters:
Slide the W/PRGM-RUN switch werem IlIIIRun to RUN.
Press Display
15 (15 The radius keyed in.
O The program running.
While the program is running, insert side 1 of the card containing
the program for the area of a circle into the card reader slot. Insert
the card until you just feel pressure against the end, then stop and
let go of the card, permitting it to ''wait'' in the card reader slot.
When the program in the calculator has gone through 100 iterations
and the value in I reaches zero, the card waiting in the card reader
slot will be read, that program merged with the program already in
the calculator, and the area of the circle calculated.
If you see after the card is read, or if the card does
not pass through the card reader and you see , Temove
the card, clear the error by pressing any key, then key in the radius
again and restart the program by pressing [§. Then reinsert the
card while the program is running. When the program has run
correctly, you will see the area of the circle,| 706.86 centi-
meters, displayed.
The program from the card has merged after the instruction,
and the contents of your calculator's program memory should now
look like this:
oo1 [ B 312511
002 9 33 09
003 1 01
004 O 00
005 O 00
006 O 35 33
007 [ (B 1 31 25 01
008 [ 31 33
009 1 22 01
010 [ 32 41