Hewlett-Packard HP-10C

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: 1982-1984 Display type: Numeric display  
New price: USD 80.00   Display color: Black  
    Display technology: Liquid crystal display 
Size: 3"×5"×½" Display size: 10(7+2) digits
Weight: 4 oz    
    Entry method: Reverse Polish Notation 
Batteries: 3×"LR44" button cell Advanced functions: Trig Exp Lreg Cmem 
External power:   Memory functions: +/-/×/÷ 
I/O:      
    Programming model: Fully-merged keystroke entry 
Precision: 10 digits Program functions: Jump Cond  
Memories: 10(0) numbers Program display: Keycode display  
Program memory: 79 program steps Program editing: Overwrite capability  
Chipset:   Forensic result:  

hp10c.jpg (20138 bytes)Ah, the elusive HP-10C. The smallest member of Hewlett-Packard's Voyager family of calculators, it is surprisingly difficult to find these days. I am delighted to have gotten my hands on one that, even though it's in less than perfect cosmetic condition, still operates flawlessly.

The HP-10C has a much more limited amount of memory than its bigger cousins. At startup, you have 9 program steps and 10 memory registers available; the maximum amount of program memory is 79 program steps, with no storage registers left.

In such a limited amount of memory, it's quite difficult to implement programs such as a polynomial approximation for the Gamma function. What I have here instead is another method of approximation, using the incomplete Gamma function. With an integration limit of 24, the accuracy of the result is usually 10 digits. The program fits neatly into the calculator, with the only down side being its slow speed of execution; obtaining a result may take up to two minutes.

01	44  1	STO 1
02	 1	1
03	44  0	STO 0
04	35	CLX
05	 0	0
06	42 10	x<=y
07	22 14	GTO 14
08	45  1	RCL 1
09	44 10 0	STO÷ 0
10	 1	1
11	40	+
12	44  1	STO 1
13	22 05	GTO 05
14	 1	1
15	45  1	RCL 1
16	42 10	x<=y
17	22 23	GTO 23
18	 1	1
19	30	-
20	44 20 0	STOX 0
21	44 01	STO 1
22	22 14	GTO 14
23	 2	2
24	 4	4
25	34	x-y
26	14	yx
27	45  1	RCL 1
28	10	÷
29	44  2	STO 2
30	 2	2
31	 4	4
32	45  1	RCL 1
33	 1	1
34	40	+
35	44  1	STO 1
36	10	/
37	45  2	RCL 2
38	20	×
39	44  2	STO 2
40	40	+
41	42 10	x<=y
42	22 44	GTO 44
43	22 30	GTO 30
44	 2	2
45	 4	4
46	12	ex
47	10	÷
48	45  0	RCL 0
49	20	×
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