Hewlett-Packard HP-34C

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: 1979-1983 Display type: Numeric display  
New price: USD 150.00   Display color: Red  
    Display technology: Light-emitting diode 
Size: 5½"×3"×1" Display size: 10(8+2) digits
Weight: 8 oz    
    Entry method: Reverse Polish Notation 
Batteries: 2×"AA" NiCd Advanced functions: Trig Exp Lreg Solv Intg Cmem 
External power: HP-82087 adapter (10VAC 1.8VA)   Memory functions: +/-/×/÷ 
    Programming model: Fully-merged keystroke entry 
Precision: 10 digits Program functions: Jump Cond Subr Lbl Ind  
Memories: 21(1) numbers Program display: Keycode display  
Program memory: 210 program steps Program editing: Auto-insert program entry  
Chipset:   Forensic result:  

hp34c.jpg (20308 bytes)The HP-34C was the high-end calculator in Hewlett-Packard's Spice series. With the exception of magnetic card programmables, this was one of the highest-end programmable calculators with an LED display ever made. In addition to a full complement of scientific functions, 21 memories, and 210 steps of program storage, it had such advanced features as a numeric equation solver and a built-in numeric integration function. It also had a sophisticated programming model with labels, subroutines, flags, and indirect addressing.

As it turns out, the calculator also had a built-in implementation for the Gamma function (or, to be precise, an extended factorial function), and a pretty good one at that. It yielded accurate results for all real arguments for which the function was defined (some calculators had Gamma function implementations that worked only for positive numbers, for instance.) As a result, writing a Gamma function program was a trivial exercise:

001-25,13,11  LBL A
002-       1  1
003-      41  -
004-   25  1  x!
005-   25 12  RTN

Not exactly the pinnacle of creative calculator programming, is it. On the other hand, the calculator is not sophisticated enough, for instance, to support a Gamma function program that calculates the function's values for complex arguments. So what am I to do?

As it turns out, there is a meaningful exercise that better demonstrates the use of the HP-34C: a program that computes the incomplete Gamma function using iteration. This program, in fact, is an adaptation of the incomplete Gamma function program that appeared in the Math Pac for the HP-65, published by Hewlett-Packard. I used variations of this program on other calculators as well, such as the APF 90.

To use the program, enter the function argument and the integration limit, then press the A button.

001-25,13,11  LBL A
002-   23  1  STO 1
003-      21  x-y
004-   23  2  STO 2
005-   25  3  yx
006-   24  2  RCL 2
007-      71  ÷
008-   23  3  STO 3
009-25,13, 1  LBL 1
010-   24  1  RCL 1
011-   24  2  RCL 2
012-       1  1
013-      51  +
014-   23  2  STO 2
015-      71  ÷
016-   24  3  RCL 3
017-      61  ×
018-   23  3  STO 3
019-      51  +
020-   14 61  x!=y
021-   22  1  GTO 1
022-   24  1  RCL 1
023-   15  1  ex
024-      71  ÷
025-   25 12  RTN