HP 25 User Manual

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

HP 25 Specifications

General

Power Source	Rechargeable battery pack
Programming Steps	49
Release Year	1975
Functions	Trigonometric, logarithmic, statistical
Type	Scientific
Dimensions	148 x 80 x 14 mm