hp20s

Model:	-20S

General:
	Name:			Scientific Calculator
	Code-Name:		Erni
	Family:			Pioneer
	Logic:			algebraic w/precendence
	Features:		scientific, programmable, hyperbolic, units,
				base w/arithmetic
	Firsts:			libraries (with -21S)
	Introduction:
		Date:		1989-1-3
		Price:		$49.95
	Discontinuation:
		Date:		<2003-01-01
		Price:		?
	Production-Run:		?

Display:
	Type:			LCD, 7-segment
	Size:			1 line x 12 chars
	Number-Formats:		sign, 10 mantissa, ., exp sign, 2 exp
	Annunciators:		<\	left shift active
				/>	right shift active
				:	input has been pressed
				PEND	an operation is pending
				battery	battery low
				GRAD	grad mode
				RAD	radians mode
				HEX	hex mode
				OCT	octal mode
				BIN	binary mode
				PRGM	program mode

Data:
	User-Visible:
		Smallest:	1E-499
		Largest:	9.99999999999E499
		Signif.-Digits:	12
	Internal:
		Smallest:	1E-49999
		Largest:	9.99999999999999E49999
		Signif.-Digits:	15
	Data-Types-and-Sizes:	real, 8 bytes
				binary numbers are 36 bits

Memory:
	Named-Registers:	input, display, last result, 0-9
	Flags:			none
	Register-Usage:		R4	\GSn
				R5	\GSx
				R6	\GSy
				R7	\GSx^2
				R8	\GSy^2
				R9	\GSxy
	Numbered-Registers:	10
	Program-Steps:		99
	Program-Editing:	insert
	Program-Display:	keycode
	User-RAM-Bytes:		91
	Total-RAM-Bytes:	256
	ROM-Bytes:		10K
	Machine-State:		prefix key state
				pending operations (4 deep, not saved)
				display contrast
				display mode
				radix mark
				deg / rad / grad
				binary mode
				program counter
				four level return stack
				PRGM mode
				registers and history (not saved)
				memory
	File-Types:		none

Physical:
	Technology-Used:	CMOS
	Processor:		Bert, 640 KHz
	Chip-Count:		?
	Power-Source:		3 alkaline (Panasonic LR44) or mercury
				(Panasonic NP675) button cells
	Continuous-Memory:	yes
	Expansion-Ports:	none
	I/O-Ports:		none
	Clock:			none (10 minute timeout)

	Length:			?
	Width:			?
	Height:			?
	Weight:			?
	Temperature-Range:
		Operating:	0 to 45 deg C
		Charging:	-
		Storage:	-20 to 65 deg C

Keyboard:
	Switches:		none
	Shift-Keys:		left-shift, blue, above left
				right-shift, yellow, above right
	User-Defined-Keys:	none

Key-Arrangement::

** ** ** ** ** **
** ** ** ** ** **
***** ** ** ** **
*  ** ** ** ** **
*  ** ** ** ** **
*  ** ** ** ** **
*  ** ** ** ** **

Key-Labels-Base-Keyboard::

	 x		 x
\v/x	e	LN	y	1/x	\GS+
STO	RCL	SIN	COS	TAN	R/S
INPUT	+/-	(	)	<-
XEQ	7	8	9	\:-
<\	4	5	6	x
/>	1	2	3	-
C	0	.	=	+

(The C key has a lower label of ON.)

Key-Labels-left-shift-blue-above-left::

 2	  x
x	10	LOG	%	%CHG	\GS-
->P	HYP	ASIN	ACOS	ATAN	PRGM
SWAP	E	FIX	ENG	LOAD
GTO	v	^	ABS	IP
[]	HEX	DEC	->HR	->DEG
[]	->kg	->\^oC	->cm	->l
[]	./,	SHOW	LAST	CLRG

Key-Labels-right-shift-yellow-above-right::

x-w	x-,y-	Sx,Sy	x^,r	y^,r	m,b
->R	\pi	DEG	RAD	GRD	RTN
CLPRGM	[]	SCI	ALL	[]
LBL	x\<=y?	x=0?	RND	FP
[]	OCT	BIN	->HMS	->RAD
[]	->lb	->\^oF	->in	->gal
OFF	Cn,r	Pn,r	n!	CL\GS

Key-Labels-other::

A	B	C	D	E	F
[]	[]	[]	[]	[]	[]
[]	[]	[]	[]	[]
[]	\GSx^2	\GSy^2	\GSxy	[]
[]	n	\GSx	\GSy	[]
[]	[]	[]	[]	[]
[]	[]	[]	[]	[]

(Letters are to the right and are white.  Other labels are in gray and
to the below right.)

Programmable-Operations::

%		percent of
%CHG		percent change
(		start nesting
)		end nesting
+		addition
+/-		change sign
-		subtraction
->cm		convert inches to cm
->DEG		convert to degrees
->gal		convert liters to gallons
->HMS		convert to hours,minutes,seconds
->HR		convert to decimal hours
->in		convert mm to inches
->kg		convert lbm to kg
->l		convert gallons to liters
->lb		convert kg to lb
->P		convert rectangular to polar
->R		convert polar to rectangular
->RAD		convert to radians
->\^oC		convert deg F to deg C
->\^oF		convert deg C to deg F
./,		set radix mark
0-9, .		enter digit or decimal point
1/x		reciprocal
10^x		common exponential
=		complete the operation
ABS		absoute value
ACOS		arc cosine
ACOSH		arc hyperbolic cosine
ALL		display all of number
ASIN		arc sine
ASINH		arc hyperbolic sine
ATAN		arc tangent
ATANH		arc hyperbolic tangent
BIN		set binary mode
CLRG		clear all registers
CL\GS		clear summation registers
Cn,r		combinations
COS		cosine
COSH		arc cosine
DEC		set decimal mode
DEG		degrees mode
E		start an exponent
ENG 0-9		set ENG mode
e^x		natural exponential
FIX 0-9		set FIX mode
FP		fractional part
GRD		grads mode
GTO A-F,0-9	go to label
HEX		set hexadecimal mode
INPUT		separate two numbers
IP		integer part
LAST		recall last result
<\ LAST		store into LAST
LBL A-F,0-9	label
LN		natural logarithm
LOG		common logarithm
m,b		compute slope and y intercept
n!		factorial
OCT		set octal mode
Pn,r		permutations
R/S		start/stop a program
RAD		radians mode
RCL 0-9		recall from register
RND		round to match display
RTN		return
SCI 0-9		set SCI mode
SIN		sine
SINH		hyperbolic sine
STO +,-,x,\:- 0-9 storage arithmetic
STO 0-9		store in register
SWAP		swap displayed number with previous number
Sx,Sy		compute standard deviations
TAN		tangent
TANH		hyperbolic menu
x		multiplication
x-,y-		compute means
x-w		compute weighted average
x=0?		comparison test
XEQ A-F,0-9	call subroutine
x\<=y?		comparison test
x^,r		estimate x and correlation coefficient
x^2		square
y^,r		estimate y and correlation coefficient
y^x		power
\:-		division
\GS+		add to statistics
\GS-		subtract from statistics
\pi		constant 3.14159265359
\v/x		square root

Non-Programmable-Operations::

shift <\	clear shift
shift />	clear shift
<-		erase character or number; cancel one level of menus;
		(program mode) delete program line
C		clear number or expression; cancel all menus
C (ON)		on
C + +		adjust display contrast
C + -		adjust display contrast
C + 1/x		continuous self test, stop by C + LN
C + LN		reset calculator
C + y^x		one shot self test
C + \v/x + \GS+	clear all memory
CLPRGM		(program mode) clear all program steps
		(run mode) set program counter to 0
GTO ..		go to line 0
GTO . 00-99	go to line
GTO A-F,0-9	(run mode) set program counter to label
LOAD A-F	load built in program
OFF		off
PRGM		program/run mode
SHOW		show all digits
v		move down in list
^		move up in list

Menus::

library equations:

A	Root Finder (root)
B	Numerical Integration (int)
C	Complex Operations (CPL)
D	3 x 3 Matrix Operations (3 bY 3)
E	Quadratic Equation (qUAd)
F	Curve Fitting (Fit)

Bugs/ROM-Versions::

none

Notes::

You can use INPUT and SWAP to keep two complete calculations going at
once.  Do the first one, press INPUT, then do your second one.  Do
SWAP to switch back and forth.  Make sure that you have completed any
pending operations first.  Pressing C or turning the calculator off
and on clears both.

While basic multiplication and division follow normal precedence,
other two-input functions (e.g., %) require that their operands be
separated by the INPUT key.

When any of the libraries are used, they are copied into program
memory, replacing what is already there.  The library program can be
edited, however.

This and the 21S are the only algebraic keystroke programmable
calculators offered by HP.