Sharp EL-5150

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: 3"×7"×½" Display size: 24 characters
Weight: 6 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"CR-2032" Lithium + 1×"CR-2032" Lithium Advanced functions: Trig Exp Hyp Lreg Cmem 
External power:   Memory functions:
    Programming model: Formula programming 
Precision: 12 digits Program functions: Jump Cond Subr  
Memories: 26 numbers Program display: Formula display  
Program memory: 1454 program steps Program editing: Formula entry  
Chipset: SC61720D05, etc.   Forensic result: 8.99998153428  

el5150.jpg (37752 bytes)Like its close relative, the EL-5050, the Sharp EL-5150 is a far more powerful calculator than its unassuming appearance would suggest. It has a considerable amount of program memory, conditional execution and even a simple subroutine capability.

Programs are basically algebraic formulae, with a few special operators that allow repeated or conditional execution. A program line is limited to 160 characters, but with up to nine "subroutine" lines, it is possible to use all of program memory in a single program.

I have improved upon the demonstration program I originally wrote for the EL-5050. The version here accurately (and reasonably efficiently) computes the logarithm of the Gamma function, making use of Stirling's formula, a simple iteration, and conditional computation for negative arguments. For the program to yield correct results when the argument is negative, it is important to first place the calculator in radians mode. The program is highly accurate, yielding a full 10 digits of precision for most arguments. Newlines have been inserted here for clarity, but they don't need to be keyed in when entering this program into the calculator.

     XLN X-X+LN √(2π÷X)-LN G+((((1÷1188÷X2-1÷1680)÷X2+1÷1260)÷X2-1÷360)÷X2+1÷12)÷X⇒G
     S>0•N→[-π÷S÷SIN Sπ)-G⇒G]