Walther LC-604
| 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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Walther LC-604
Here's one more programmable calculator based on the Sharp LI3301A chipset: this Walther LC-604 joins the ranks of over a dozen such calculator from many different manufacturers in my possession.
The programming model of this chipset is very limited and idiosyncratic. My usual programming example therefore was a rather inaccurate approximation of the Gamma function based on Stirling's formula. Recently, however, Robert H. Windschitl discovered an approximation formula that is especially suited for calculators with limited programmability, and provides greater accuracy than solutions based on the "pure" versions of Stirling's formula:
X-M 1 M+ RM 1/x HYP SIN × RM = √ × RM ÷ 1 ex = Yx RM × ( 2 × π ÷ RM ) √ =
