HP HP-67 - The I-Register

Storing and Recalling Numbers 73
For example, to recall Avogadro’s number from register Ry:
Press Display
2 6.020000000 23
To recall the square of Avogadro’s number from register Rg:
Press Display
Q 3.624040000 47
When you recall a number, it is copied from the storage register
into the display, and it also remains in the storage register. You can
recall a number from a storage register any number of times without
altering it—the number will remain in the storage register as a 10-digit
number with a two-digit exponent of 10 until you overwrite it by
storing another number there, or until you clear the storage registers.
For example, even though you earlier recalled Avogadro’s number
from storage register R,, you can recall it again:
Press Display
2 6.020000000 23
The I-Register
The I-register has a number of special properties that make it useful in
programming, but these will be discussed later. The simplest function
of the I-register is its use as another of the primary storage registers in
your HP-67. To store a number in the I-register, press @ (store
I). To then recall that number from the I-register into the display, press
(recall I).
Example: Three tanks have capacities in U.S. units of 2.0, 14.4,
and 55.0 gallons, respectively. If 1 U.S. gallon is equivalent to
3.785 liters, what is the capacity of each of the tanks?
Method: Place the conversion constant in one of the storage registers
and bring it out as required.