Radio Shack EC-4023

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:   Display type: Alphanumeric display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 5"×3"×½" Display size: 12 characters
Weight: 4 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"CR-2032" Lithium Advanced functions: Trig Exp Hyp Lreg Cmem BaseN Eqlib 
External power:   Memory functions: +/- 
I/O:      
    Programming model: Formula programming 
Precision: 11 digits Program functions:  
Memories: 10 numbers Program display: Formula display  
Program memory: 675 program steps Program editing: Formula entry  
Chipset: Casio fx-5000F   Forensic result:  

ec4023.jpg (22694 bytes)Yet another Radio Shack OEM machine: this one is the Casio fx-5000F calculator in disguise. An excellent calculator with a generous 675-step formula memory, and 128 built-in scientific formulae that can be executed, or recalled into editable formula memory. Sadly, no branching or conditional execution capability is offered; an already useful machine, the EC-4023 would be one of my favorites with that kind of programming flexibility.

The roomy formula memory is more than sufficient to store a polinomial implementation of my favorite programming example, the Gamma function. Here it is again (this is the same formula I wrote for the fx-5000F):

(1+76.18009173/(Ans+1)-86.50532033/(Ans+2)+
24.01409824/(Ans+3)-1.231739572/(Ans+4)+
1.208650974E-3/(Ans+5)-5.395239385E-6/(Ans+6))
√2π/Ans×(Ans+5.5)xy(Ans+.5)/e(Ans+5.5)

The method used here makes the formula operate on the result of any previous calculation, rather than prompting for the values of any independent variables.