Hewlett-Packard HP-41CX

Datasheet legend
Ab/c: Fractions calculation
AC: Alternating current
BaseN: Number base calculations
Card: Magnetic card storage
Cmem: Continuous memory
Cond: Conditional execution
Const: Scientific constants
Cplx: Complex number arithmetic
DC: Direct current
Eqlib: Equation library
Exp: Exponential/logarithmic functions
Fin: Financial functions
Grph: Graphing capability
Hyp: Hyperbolic functions
Ind: Indirect addressing
Intg: Numerical integration
Jump: Unconditional jump (GOTO)
Lbl: Program labels
LCD: Liquid Crystal Display
LED: Light-Emitting Diode
Li-ion: Lithium-ion rechargeable battery
Lreg: Linear regression (2-variable statistics)
mA: Milliamperes of current
Mtrx: Matrix support
NiCd: Nickel-Cadmium rechargeable battery
NiMH: Nickel-metal-hydrite rechargeable battery
Prnt: Printer
RTC: Real-time clock
Sdev: Standard deviation (1-variable statistics)
Solv: Equation solver
Subr: Subroutine call capability
Symb: Symbolic computing
Tape: Magnetic tape storage
Trig: Trigonometric functions
Units: Unit conversions
VAC: Volts AC
VDC: Volts DC
Years of production: 1983-1990 Display type: 14-segment alphanumeric  
New price: USD 325.00   Display color: Black  
    Display technology: Liquid crystal display 
Size: 5½"×3"×1" Display size: 12 14-segment characters
Weight: 7 oz    
    Entry method: Reverse Polish Notation 
Batteries: 4×"N" alkaline Advanced functions: Trig Exp Lreg Cmem RTC Snd 
External power: HP adapter (with battery pack)   Memory functions: +/-/×/÷ 
I/O: expansion ports     
    Programming model: Fully-merged keystroke entry 
Precision: 10 digits Program functions: Jump Cond Subr Lbl Ind  
Memories: 319(0) numbers Program display: Mnemonic display  
Program memory: 2233 bytes Program editing: Auto-insert program entry  
Chipset: Nut   Forensic result: 9.000417403  

hp41cx.jpg (24548 bytes)Hewlett-Packard's HP-41 line of calculators were the first pocket calculators to offer alphanumeric display capability. These calculators had a beautiful, high-contrast 14-segment alphanumeric display, capable of showing up to 12 characters at a time. The calculators also had, in addition to the comfortably large internal memory, four expansion ports to which additional memory modules and other peripherals could be attached. I'm tempted to say that the HP-41 was ahead of its time but it really wasn't: it was right on the mark, appearing just as it became possible to produce a calculator system with advanced capabilities and a rich set of peripherals for a reasonable price.

The CX model of the HP-41 line was the most advanced, offering extra built-in memory, timer functions, and other features.

These calculators are keystroke programmable, like their predecessors. However, the alphanumeric display makes it possible for the calculator to display key mnemonics instead of numeric keycodes, making programming that much easier.

The HP-41 programming model is fully merged, with a variable instruction word length. Many instructions use a single byte of memory, but some can take several bytes; for instance, as the program below demonstrates, alpha or numeric constants both appear as a single program line.

This program below is, of course, yet another implementation for the Gamma function. It calculates the Gamma function for any real argument. The program can be invoked by typing XEQ ALPHA G A M M A ALPHA; alternatively, the function can be assigned to a user key.

01	LBL'GAMMA
02	1
03	X<>Y
04	LBL 02
05	X>0?
06	GTO 01
07	ENTER^
08	RDN
09	*
10	R^
11	1
12	+
13	GTO 02
14	LBL 01
15	STO 01
16	X<>Y
17	STO 00
18	76.18009173
19	RCL 01
20	1
21	+
22	/
23	86.50532033
24	RCL 01
25	2
26	+
27	/
28	-
29	24.01409824
30	RCL 01
31	3
32	+
33	/
34	+
35	1.231739572
36	RCL 01
37	4
38	+
39	/
40	-
41	1.208650974 E-3
42	RCL 01
43	5
44	+
45	/
46	+
47	5.395239385 E-6
48	RCL 01
49	6
50	+
51	/
52	-
53	1
54	+
55	PI
56	2
57	*
58	SQRT
59	*
60	RCL 01
61	/
62	LN
63	RCL 01
64	5.5
65	+
66	LN
67	RCL 01
68	.5
69	+
70	*
71	+
72	RCL 01
73	-
74	5.5
75	-
76	E^X
77	RCL 00
78	/
79	RTN