Casio fx-180P

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: 1980  Display type: Numeric display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 6"×3"×½" Display size: 10+2 digits
Weight: 5 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"AA" alkaline Advanced functions: Trig Exp Lreg Intg Ab/c Cmem 
External power:   Memory functions: +/-/×/÷ 
    Programming model: Fully-merged keystroke entry 
Precision: 11 digits Program functions: Cond  
Memories: 7 numbers Program display:  
Program memory: 38 program steps Program editing:  
Chipset:   Forensic result:  

fx180p.jpg (27575 bytes)An archetypical programmable calculator from Casio, the fx-180P has many of the distinguishing features found in the vast majority of non-graphing programmable Casio calculators. 38 merged program steps, 6 registers plus one "independent" memory, a simple programming model that nevertheless provides for conditional execution, and an uncluttered keyboard offering a comprehensive set of scientific and statistical functions characterize this model and many of its successors.

38 program steps is not a heck of a lot, but thanks to the merged programming model, it is sufficiently large for a quality implementation of my favorite programming example, the Gamma function. The program below uses the Lanczos-approximation to compute the logarithm of the Gamma function to (typically) 10 digits of precision for all positive arguments.

Kin 1
Kout 3
Kout 2
Kout 4
Kin+ 1
Kout 1
Kout 5
Kin+ 1
Kout 1
Kout 1
Kout 6
Kout 1