Radio Shack EC-4004
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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Radio Shack EC-4004
The EC-4004 is a Radio Shack OEM version of the venerable Casio fx-3600P programmable calculator.
At first, I seriously underestimated the capabilities of this machine. 38 program steps? A conditional loop-to-start instruction as the only means of branching? Surely, that's not enough to do anything useful, certainly not something as complex as my favorite programming example, the Gamma function.
Well, I was wrong. This machine is more capable than I thought, due in part to the fact that it offers four-function memory arithmetic on its six K-registers. Moreover, these 3-keystroke instructions count only as a single step in program memory. Impressive! A fellow calculator enthusiast already sent me an implementation of the incomplete Gamma function (see my fx-3600P page for the listings.)
Of course, if you don't want to key in a complex and slow program, and you can use results with more limited accuracy, you can still make use of Stirling's formula:
Min × 2 × π = √ × MR xy MR ÷ MR ex × ( 1 2 1/x ÷ MR + 1 =