HP (Hewlett-Packard) HP-42S Calculator User Manual


 
ABCDE FGHI JKLM NOPQ RSTUV WXYZ
These are sub-menus. If you press now ABCDE what you will have is
A B C D E
Then just pick the letter you want. But above you can see this symbol ▼▲.
This symbol means the menu has more than on line. You can access the
other lines by pressing ▲ or ▼. In this case there is just one more line with
Ă, Å and Æ. If you press FGHI you will have F G H I, etc.
Among all calculators I know this is in my opinion the best way to enter
letters!
The main ALPHA menu also have ▼▲ symbol. The other line has the
following submenus.
([{ ←↑↓ <=> MATH PUNC MISC, much more than one will ever
need! If you are inside a submenu and want to go back to main menu just
press EXIT.
Why is alpha menu useful? Of course it is useful to label programs, data
in memory but it is also useful to enter commands using XEQ key! For
example XEQ “SIN” is the same of pressing SIN key. The “” are called
automatically when pressing ▀ ALPHA and ENTER. XEQ “SINH”
calculates the hyperbolic sinus while XEQ “OFF” turns the calculator off.
Finally we must say that ▀ ALPHA is not always needed! In some cases
like XEQ, GTO (we will see this later) a simple ENTER will do.
x><y and ▀ LASTx: We already talked about.
+/-: This just change the sign of a number.
E and ▀ DISP: We already talked about DISP menu but what would be E? The E is the character
meaning the power of 10 in scientific notation. For example, to enter 5.2x
10
22
we
do 5 . 2 E 22 ENTER.
and ▀ CLEAR: As said before clears line x and if you are entering a number you can delete
the last character. We already talked a little about CLEAR menu and we will
discuss it again later.
▲ or ▼: As said before we use this to change the line in a multi line menu. We will see ▀ BST and
▀ SST later.
The keys from 0 to 9 have obvious functions.
. and ▀ SHOW: The '.' is just the decimal point and ▀ SHOW is used to show a number for an
instant with all precision. For example: If you have π in the first line and you are
using the display in FIX 4 you have 3.1416 but pressing ▀ SHOW you will see
3.14159265359 for an instant.
We stop studying the keyboard here for now.