HP HP-16C - Calculations Withconstants

26 Section 2: The Automatic Memory Stack
For example, consider the (integer decimal) calculation
3[4+ 506+17)].
Keystrokes Display
DEC Display shows last
result.
6 7 13 d Intermediate result.
5 [x] 65 d Intermediate result.
4 69 d Intermediate result.
3[x] 207 d Finalresult.
This example shows that the stack automatically drops after each
two-number calculation and lifts when a new number is
subsequently keyed in.
Calculations With Constants
There are two ways (without using a storage register) to perform
repeated calculations with a constant:
e Usethe LAST X register.
® Load the stack with the constant prior to doing the
computations.
Example: Remove the upper four bits and preserve the lower four
bits from the following 8-bit binary numbers: 10001001, 10101111,
and 11110101. The constant value 1111 will be used as a mask.
Using the LAST X Register. Make sure to calculate with the
constant in the X-register (rather than the Y-register) so that it will
always be saved in the LAST X register. Retrieve the constant by
pressing [9](LSTx].
Keystrokes Display
Binary mode. Display
shows previous rsult.
10001001 10001001 b First number.
1111 1111 b The mask (the constant).
1001 b Lower four bits.