HP 25 - Section 4: Function Keys; Last X

Section 4
Function Keys
The H P-25 function keys can be used manually or keyed in as
p
art of a program. In this section, each key is individually ex-
plained . To use function keys manually , ensure that the
PROM-RUN switch PRGM" RUN is set to RUN.
LAST X
In add iti on to the four st ack registers that automatica ll y store
int ermed i ate r esu lts, the H P-25 also cont ains a separate auto-
matic register , the LAST X register. T hi s regis ter preserves
the value that was in the displayed X -r egister before the per-
formance of a function. To place the content s of the LAST X
register into the display again, pres s c=J .
Recovering from Mistakes
I L AST X I makes it easy to recover from keystroke mistakes,
such as pressing the wrong function key or keying in the wrong
numb er.
Example: Divide 12 by 2. 157 after you have mi s taken ly div id ed
by 3. 157.
Pre ss Display
12
mum
3.1578
a I LASH I
o
2. 1 578
1
1
2.
1
12.00
1
3
.
8
0
I 3.16
1
12
.
0
0
15.
56
Oops! You made a mistake .
Retrieves that last entry .
You're back at the beginning.
The correct ans wer.
49