Casio fx-5500L

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: 1990  Display type: Alphanumeric display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 5½"×3"×½" Display size: 2×16 characters
Weight: 5 oz    
    Entry method: Formula entry 
Batteries: 2×"CR-2032" Lithium + 1×"CR-2032" Lithium Advanced functions: Trig Exp Hyp Lreg Intg Ab/c Cplx Cmem Mtrx BaseN 
External power:   Memory functions: +/- 
    Programming model: Formula programming 
Precision: 12 digits Program functions:  
Memories: 26 numbers Program display: Formula display  
Program memory: 1095 program steps Program editing: Formula entry  
Chipset:   Forensic result: 9.00001568547  

fx5500l.jpg (20546 bytes)A somewhat atypical model, the Casio fx-5500L is a scientific calculator with limited programmability in the form of formula storage. It does have a fair amount of space for formula storage, but it lacks conditional expressions and other forms of program control.

Storage for formulae in this calculator is organized in two levels. A single formula can be stored, recalled, and executed in a current storage area. Additional formulae can be stored in the formula memory, and recalled into the current storage area for execution.

For instance, consider my standard example, the Gamma function, for which a formula is provided below. To add this formula to the calculator's formula memory, first enter the formula, then press [Shift] [CALC] [SET]. Later, the formula can be recalled by pressing [Shift] [CALC] [f], using the up and down-arrow keys to locate the desired formula, and then by pressing the [IN] button to move the formula to the current storage area.

To compute the Gamma function (actually, the natural logarithm thereof) to 10+ digit accuracy for arguments greater than 5, you can use Stirling's formula as follows:

G=X×ln X-X+ln √(2×π/X)+((((1/1188/X²-1/1680)/X²+1/1260)/X²-1/360)/X²+1/12)/X