Hewlett-Packard HP-28C
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-28C
The HP-28C was a short-lived version of Hewlett Packard's more popular HP-28S calculator. Unlike the HP-28S with its 32 kB of RAM, the HP-28C had only a miserable 2 kB. Otherwise, the two calculators were identical.
According to calculator folklore, HP quickly realized that only 2 kB of memory is simply not enough to take advantage of the amazing capabilities this machine has to offer. Which is why, shortly after its introduction, the 28C was replaced with the 28S and disappeared form store shelves. Which may explain why this calculator is a bit difficult to find nowadays.
Well, on a calculator with too little memory, it only makes sense to save some, even if it's at the expense of processing time. So rather than presenting yet another copy of my usual Gamma function programming example, here's a program that calculates the incomplete Gamma function. This program can also be used to approximate the regular Gamma function by specifying a high enough integration limit; for instance, 5 ENTER 50 IGAMMA (assuming the program is saved under the name IGAMMA) yields 24, the exact value of the Gamma function of 5.
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