Hewlett-Packard HP-19BII
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 |
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Hewlett-Packard HP-19BII
The clamshell design of the HP-19B calculator must obviously have been popular: that machine's direct successor, the HP-19BII, was still sold by Hewlett-Packard more than ten years after its introduction.
Like its predecessor, the HP-19BII also has the "SOLVE" feature as a form of programmability, and includes the conditional function IF and the summation function Σ.
The example I developed for this calculator is an implementation of the Gamma function, extended over the domain of negative numbers with the use of the conditional and summation functions.
G=(-1)^Σ(I:X:0:1:1)÷EXP(Σ(I:X:15:1:LN(ABS(i))))× L(Q,Σ(I:X:15:1:1)+X)^Q÷EXP(Q)×SQRT(2×PI÷Q)× EXP(((((1÷1188÷SQ(Q)-1÷1680)÷SQ(Q)+1÷1260)÷SQ(Q)-1÷360)÷SQ(Q)+1÷12)÷Q)