hp41c

Model:	-41C

General:
	Name:			Handheld Computer
	Code-Name:		Coconut
	Family:			Coconut
	Logic:			RPN
	Features:		scientific, programmable
	Firsts:			Coconut, alpha, ports, user keyboard,
				CMOS/SOS CPU
	Introduction:
		Date:		1979-07-01
		Price:		$295
	Discontinuation:
		Date:		1985-01-01
		Price:		$195
	Production-Run:		1.5 million (all types)

Display:
	Type:			LCD, 17 segments
				 --
				|\/|
				 -- .
				|/\|.
				 -- ,
	Size:			1 line x 12 chars
	Number-Formats:		sign, 10 mantissa
				sign, 8 mantissa, ., exp sign, 2 exp
	Annunciators:		BAT	low battery
				USER	user mode active
				GRAD	grads mode
				RAD	radians mode
				SHIFT	shift key pressed
				0	flag 0 set
				1	flag 1 set
				2	flag 2 set
				3	flag 3 set
				4	flag 4 set
				PGRM	program mode
				ALPHA	alpha keyboard active

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, high nybble of 0 or 9
				alpha, 7 bytes (6 chars), high nybble of 1

Memory:
	Named-Registers:	X, Y, Z, T, Last x, Alpha (24 chars), 00-99
	Flags:			56, of which 0-31 are user and 32-55 are
				system (and can only be affected indirectly)
				0-4	show annunciator when set
				11	auto execution
				12	print double wide
				13	print lower case
				14	card reader allow overwrite
				15	HPIL printer: 0)manual 1)normal
					2)trace 3)trace w/stack print
				17	record incomplete
				18	IL interrupt enable
				21	printer enabled
				22	numeric input available
				23	alpha input available
				24	ignore range errors
				25	ignore any errors & clear
				26	audio output is ignored
				27	user mode is active
				28	radix mark: 0). 1),
				29	digit groupings shown: 0)no 1)yes
				30	catalog set
				31	date mode: 0)M.DY 1)D.MY

				32	IL man I/O mode
				33	can control IL
				34	prevent IL auto address
				35	disable auto start
				36	number of digits, 0-15
				40	display format: 0)sci 1)eng 2)fix
					3)fix/eng mode)
				42	angle mode: 0)deg 1)rad 2)grad 3)rad
				44	continuous on
				45	system data entry
				46	partial key sequence
				47	shift key pressed
				48	alpha keyboard active
				49	low battery
				50	set when a message is displayed
				51	single step mode
				52	program mode
				53	IL I/O request
				54	set during pause
				55	printer exists
	Register-Usage:		(status registers)
				0	T
				1	Z
				2	Y
				3	X
				4	L
				5	M,[	alpha, chars 7-1
				6	N,\	alpha, chars 14-8
				7	O,]	alpha, chars 21-15
				8	P,^	scratch; alpha, chars 24-22
				9	Q,_	scratch
				10	|-,t	unshifted key assignments;
						 scratch
				11	a	return stack, levels 6-3b
				12	b	return stack, levels 3a-1; pc
				13	c	statistics ptr; scratch;
						169; R00 pointer; .END. ptr
				14	d	flags
				15	e	shifted key assignments;
						scratch, program line number

				(default assignment; can be changed)
				R11	\GSx
				R12	\GSx^2
				R13	\GSy
				R14	\GSy^2
				R15	\GSxy
				R16	\GSn
	Numbered-Registers:	64
	Program-Steps:		000-999
	Program-Editing:	insert
	Program-Display:	alpha
	User-RAM-Bytes:		560
	Total-RAM-Bytes:	maximum is 16 status registers, 64
				built-in registers, 4 64-register memory
				modules or 2,352 bytes; in addition,
				there can be extended memory totalling
				127 + 2 * 238 registers or 4,221 bytes;
				total memory can thus be 6,573 bytes
	ROM-Bytes:		12K (10-bit words)
	Machine-State:		status regs
				stack lift enable
				memory
	File-Types:		data, text, program (see LIF)

Physical:
	Technology-Used:	CMOS/SOS
	Processor:		Nut
	Chip-Count:		CPU, 1-3 ROMs, RAM(s), display driver,
				power supply, timer (-CX only)
		old -C and -CVs use 3, 40 Kbit ROMs
		newer -C and -CVs use 1, 120 Kbit ROM
		-CX uses 2, 120 Kbit ROMs

		early -Cs use 5 RAMs, each with 16 registers
		newer units use one 16 register RAM, and N 64 register RAMs

		original CPU was based on that used for the -25C and
		whose instruction set is similar to that of the -21A
	Power-Source:		4 1.5V N cells
	Continuous-Memory:	yes
	Expansion-Ports:	4
	I/O-Ports:		beeper (HP-IL, card reader, printer, etc.
				available for expansion ports)
	Clock:			no

	Length:			14.27 cm
	Width:			7.86 cm
	Height:			3.33 cm
	Weight:			205 g
	Temperature-Range:
		Operating:	0 to 45 deg C
		Charging:	-
		Storage:	-20 to 65 deg C

Keyboard:
	Switches:		ON	\ each side of a single,
				USER	/ dual rocker wipe
				PRGM	\ each side of a single,
				ALPHA	/ dual rocker wipe
	Shift-Keys:		gold, gold, above
				alpha, white, below on face
	User-Defined-Keys:	all

Key-Arrangement::

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

Key-Labels-Base-Keyboard::

\GS+	1/x	\v/x	LOG	LN
x<>y	Rv	SIN	COS	TAN
[]	XEQ	STO	RCL	SST
ENTER^	CHS	EEX	<-
-	7	8	9
+	4	5	6
x	1	2	3
\:-	0	.	R/S

Key-Labels-gold-gold-above::

	 x	 2	  x	 x
\GS-	y	x	10	e
		   -1	   -1	   -1
CL\GS	%	SIN	COS	TAN
[]	ASN	LBL	GTO	BST
CATALOG	ISG	RTN	CLx/A
x=y?	SF	CF	FS?
x\<=y?	BEEP	P->R	R->P
x>y?	FIX	SCI	ENG
x=0?	\pi	LASTx	VIEW

Key-Labels-Alpha-White-Below-On-Face::

A	B	C	D	E
F	G	H	I	J
[]	K	L	M	[]
N	O	P	[]
Q	R	S	T
U	V	W	X
Y	Z	=	?
:	SPACE	,	[]

Key-Labels-Alpha-Shifted-Not-Shown::

a	b	c	d	e
\GS	%	\=/	<	>
[]	|-	ASTO	ARCL	BST
\^|	\<)	$	CLA
-	7	8	9
+	4	5	6
*	1	2	3
/	0	.	AVIEW

Programmable-Operations::

%		percent
%CH		percent change
+		addition
-		subtraction
0-9, .		enter digit or decimal point
1/X		inverse
10^X		common exponent
ABS		absolute value
ACOS		arc cosine
ADV		paper advance
AOFF		alpha keyboard off
AON		alpha keyboard off
ASHF		alpha shift
ASIN		arc sin
ASTO %%%	alpha store
ATAN		arc tangenet
AVIEW		alpha view
BEEP		beep
CF 00-29	clear flag
CHS		change sign
CLA		clear alpha
CLD		clear display
CLRG		clear registers
CLST		clear stack
CLX		clear x
CL\GS		clear summation registers
COS		cosine
D-R		convert degrees to radians
DEC		convert octal to decimal
DEG		set degrees mode
DSE %%%		decrement and skip if equal
EEX		enter exponent
END		end program
ENG 0-9		engineering notation
ENTER^		enter
E^X		natural exponent
E^X-1		natural exponent - 1
FACT		factorial
FC? 00-55	is flag clear
FC?C 00-29	is flag clear and clear
FIX 0-9		fixed notation
FRC		fractional part
FS? 00-55	is flag set
FS?C 00-29	is flag set and clear
GRAD		set grads mode
GTO label	goto
HMS		convert decimal hours to H.MS
HMS+		add two times in H.MS notation
HMS-		subtract two times in H.MS notation
HR		convert H.MS to decimal hours
INT		integer part
ISG %%%		increment and skip if greater
LASTX		recall last x
LBL label	label
LN		natural logarithm
LN1+X		natural logarithm + 1
LOG		common logarithm
MEAN		compute average
MOD		modulus
OCT		convert decimal to octal
OFF		turn off
P-R		convert polar to rectangular
PI		constant pi
PROMPT		display a prompt
PSE		pause
R-D		convert radians to degrees
R-P		convert rectangular to polar
R/S		run / stop
RAD		set radians mode
RCL %%%		recall
RDN		roll down
RND		round
RTN		return
R^		roll up
SCI 0-9		scientific notation
SDEV		standard deviation
SF 00-29	set flag
SIGN		sign of number
SIN		sine
SQRT		square root
ST+ %%%		storage arithmetic
ST- %%%		storage arithmetic
STO %%%		store
STOP		stop
STx %%%		storage arithmetic
ST\:- %%%	storage arithmetic
TAN		tangent
TONE 0-9	tone
VIEW %%%	view
x		multiplication
X<0?		comparison test
X<> %%%		swap X and register
X<>Y		swap
X<Y?		comparison test
X=0?		comparison test
X=Y?		comparison test
X>0?		comparison test
X>Y?		comparison test
XEQ label	subroutine call
XROM ###,###	xrom call
X\<=0?		comparison test
X\<=Y?		comparison test
X\=/0?		comparison test
X\=/Y?		comparison test
X^2		square
Y^X		exponentiation
\:-		division
\GS+		summation plus
\GS-		summation minus
\GSREG 00-99	set summation register
\GSREG?		what is summation register pointer
|-		append

%%% is a register designator; it can be 00-99,X,Y,Z,T,L.  It can also
have a leading . (displays as IND) which designates indirection.

Non-Programmable-Operations::

<-		clear digit or entry
ALPHA		toggle alpha mode
ASN		assign user key
BST		back step
CAT 1-3		catalogs: 1) user programs, 2) external functions,
		3) built-in functions
CLP label	clear program
COPY label	copy program
DEL 000-999	delete N program line lines
GTO . 000-999	go to line number
GTO . EEX 000-999 go to line number
GTO . label	go to label
ON		turn on or off
ON + <-		clear all memory
PACK		pack memory
PRGM		toggle program mode
SIZE 000-999	set curtain
SST		single step
USER		toggle user mode

Menus::

none

Bugs/ROM-Versions::

#1: Early machines did not save X into L when \GS+ and \GS- were done.

#2: Early machines allowed RCL IND nn and STO IND nn when nn was
outside the memory range.

#3: Early machines allowed SF,CF,FS?C, and FC?C IND nn with nn any
number (but not a stack register) 0 to 55.

#4: Early models compute the SIN of small angles incorrectly.

#5: CLP would only clear 1089 program lines.

#6: -67A/-97A prorams that contain combinations of number entry, EEX,
and CHS do not translate correctly.  Example:

	EEX	CHS	7	CHS	5

translates to

	E-7-5

instead of

	1E-7	-5

#7: The second nybble of the seventh byte of Alpha is copies along
with the first six bytes during an ASTO.

#8: Early machines do not decompile programs if they are turned off
during PRGM mode.

#9: Executing CAT 1 while in PRGM mode, then interrupting it with R/S
causes step labelling oddities.

#10: If flag 25 is set and MEAN or SDEV causes an overflow, some flags
can be altered.

#11 (CW1): If a program at the end of CAT 1 is replaced or deleted, a
return to that program will return into the new program or off-program
memory.

#12: On early models, the function LN(1+X) gives wrong answers for
values of X between -.9990234374 and -1.00.

#13: On early models, the operation (.1)^-43 gives an answer of
9.999999999E42 instead of 1E43.

ROM Versions:

	version	date codes	comments
	DDE	1926-1940	all bugs
	FDE	1936-1952	#3 removed
	FEE	1951-2034	#1,#2,#4 removed
	GFF	2035-84??	#5,#7,#8 removed, first -41CV version
	HFF	84??-present	current -41CV version
	NFL	2329-present	current -41CX version

Notes::

Probably the most popular HP handheld ever made.  Huge amounts have
been written about this machine.  An excellent detailed reference is
"Extend Your HP-41" by Wlodek (W.A.C.) Mier-Jedrzejowicz, Synthetix:
Berkeley, California, 1985..

price changes:

	1981-01-01	$250
	1982-11-01	$195

Jeremy Smith's price list also lists:

-41CC introduced 1981-01-15 at $495, discontinued 1981-06-01.
-41CS introduced 1981-01-15 at $840, discontinued 1981-06-01.

and from eric@apache.Telebit.COM (Eric Smith):

	According to HP Key Notes Vol. 4 No. 3 dated
	September-December 1980, page 12, HP introduced the HP-41
	System I and HP-41 System II.

	The System I is an HP-41CV and Card Reader combination for $495.

	The System II is an HP-41CV, Card Reader, and Printer
	combination for $840.

	As you can see, the prices match, although the article doesn't
	give the -41CC or -41CS desginations.

Battery current:

	mode	typical	worst

	run	10 mA	15 mA
	standby	1 mA	1 mA
	sleep	10 uA	30 uA