hp31e

Model:	-31E

General:
	Name:			Scientific Calculator?
	Code-Name:		Ginger
	Family:			Spice, Series 30, Series E
	Logic:			RPN
	Features:		scientific
	Firsts:			Spice series (with -33E and -38E)
	Introduction:
		Date:		1978-5-1
		Price:		$60
	Discontinuation:
		Date:		1980-02-01
		Price:		$50
	Production-Run:		?

Display:
	Type:			LED, 7 segment
	Size:			1 line x 10 chars
	Number-Formats:		sign,  10 mantissa
				sign, 7 mantissa, ., exp sign, 2 exp
	Annunciators:		raised .	battery low

Data:
	User-Visible:
		Smallest:	1E-99
		Largest:	9.999999999E99
		Signif.-Digits:	10
	Internal:
		Smallest:	1E-99
		Largest:	9.999999999E99
		Signif.-Digits:	10
	Data-Types-and-Sizes:	real, 7 bytes

Memory:
	Named-Registers:	X, Y, Z, T, Last x
				0-3?
	Flags:			none
	Register-Usage:		none
	Numbered-Registers:	4
	Program-Steps:		0
	Program-Editing:	none
	Program-Display:	none
	User-RAM-Bytes:		56
	Total-RAM-Bytes:	?
	ROM-Bytes:		?
	Machine-State:		prefix key state
				stack lift enable
				display mode
				registers
	File-Types:		none

Physical:
	Technology-Used:	?
	Processor:		?
	Chip-Count:		?
	Power-Source:		custom nickel-cadmium 2 AA cell pack, A/C
	Continuous-Memory:	no
	Expansion-Ports:	none
	I/O-Ports:		none
	Clock:			none

	Length:			140mm (5.6")
	Width:			75mm (3.0")
	Height:			30mm (1.2")
	Weight:			220g (7.7oz)
	Temperature-Range:
		Operating:	0 to 45 deg C
		Charging:	15 to 40 deg C
		Storage:	-40 to 55 deg C

Keyboard:
	Switches:		OFF / ON
	Shift-Keys:		f, yellow, above
	User-Defined-Keys:	none

Key-Arrangement::

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

Key-Labels-Base-Keyboard::

		 x	 x
\v/x	1/x	y	e	LN
x<>y	Rv	STO	RCL	f
ENTER^	CHS	EEX	CLx
-	7	8	9
+	4	5	6
x	1	2	3
\:-	0	.	%

Key-Labels-f-gold-above::

			  x
FIX	SCI	\pi	10	LOG
DEG	RAD	GRAD	LAST x	[]
|--------- CLEAR ---------|
MANT PREFIX	ALL	REG	STK
->R	SIN	COS	TAN
	   -1	   -1	   -1
->P	SIN	COS	TAN
->DEG	->in	->\^oF	->lbm
->RAD	->mm	->\^oC	->kg

Programmable-Operations::

none

Non-Programmable-Operations::

%		percent of
+		addition
-		subtraction
->DEG		convert to degrees
->in		convert mm to inches
->kg		convert lbm to kg
->lbm		convert kg to lbm
->mm		convert inches to mm
->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
0-9, .		enter digit or decimal point
1/x		reciprocal
10^x		common exponentiation
ALL		clear all registers
CHS		change sign
CLx		clear X
COS		cosine
COS-1		arc cosine
DEG		degrees mode
EEX		start an exponent
ENTER^		enter
e^x		natural exponentiation
f		f-shift
FIX 0-9		FIX mode
GRD		grads mode
LN		natural logarithm
LOG		common logarithm
LAST x		LAST X
MANT		temporarily display all matissa digits
PREFIX		clear any prefix
RAD		radians mode
RCL 0-3		recall from register
REG		clear registers
Rv		roll the stack down
SCI 0-9		SCI mode
SIN		sine
SIN-1		arc sine
STK		clear stack
STO +,-,x,\:- 0-3	storage arithmetic ?
STO 0-3		store in register
STO ENTER^	self-test, clears memory
TAN		tangent
TAN-1		arc tangent
x		multiplication
x<>y		exchange x and y
y^x		power
\:-		division
\pi		constant, value 3.141592654
\v/x    	square root

Menus::

none

Bugs/ROM-Versions::

none

Notes::

The machines in the original Spice series (the "E"s and early "C"s)
were notorious for having one or more columns/rows of keys go dead.
This was due to corrosion and foil separation on the through-board
connector.