Appendix B: Stack Lift and the LAST X Register 211

T

Z

Y

X

Keys:

y

 

y

 

y

 

 

 

 

 

x

 

x

 

x

 

 

 

 

 

4.0000

 

53.1301

 

53.1301

 

 

 

 

 

3

 

5.0000

 

0.0000

 

 

 

 

 

: ` 7

Stack Stack

enabled. disabled.

y

x

53.1301

7

No stack

lift.

Imaginary X-Register.All enabling functions provide for a zero to be placed in the imaginary X-register when the next number is keyed or recalled into the display.

Neutral Operations

Stack Lift. Some operations, like , are neutral; that is, they do not alter the previous status of the stack lift. Thus, if you disable the stack lift by pressing v, then press ´•n and key in a new number, that number will write over the number in the X-register and the stack will not lift. Similarly, if you have previously enabled the stack lift by executing, say ¤, then execute a instruction followed by a digit entry sequence, the stack will lift.*

The following operations are neutral on the HP-15C:

• g U ¦

it “ nnn CLEAR u ¥

^

CLEAR Q %

D

Â

CLEAR ∑

R

W

©

Imaginary X-Register.The above operations are also neutral with respect to clearing the imaginary X-register.

*All digit entry functions are also neutral during digit entry. After digit entry termination, and are lift enabling, is disabling.

That is, the ´ %sequence used to view the imaginary X-register.

Page 211
Image 211
HP 15c Scientific manual Neutral Operations, Appendix B Stack Lift and the Last X Register Keys, Nnn Clear u ¥