Sharp EL-5500II

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"×7½"×½" Display size: 24 characters
Weight: 5 oz    
    Entry method: BASIC expressions 
Batteries: 2×"CR-2032" Lithium Advanced functions: Trig Exp Hyp Lreg Cmem Snd 
External power:   Memory functions:
I/O: Interface port     
    Programming model: BASIC 
Precision: 12 digits Program functions: Jump Cond Subr Lbl Ind  
Memories: 3742(208) bytes Program display: Text display  
Program memory: 3534 bytes Program editing: Text editor  
Chipset:   Forensic result:  

el5500ii.jpg (33960 bytes)The Sharp EL-5500II is a vintage BASIC calculator. Like other Sharp models in the EL-5500 series, this calculator also has two distinct operating modes. In calculator mode, the numeric keypad functions as a powerful, but non-programmable scientific calculator. In BASIC mode, the calculator can store and execute one BASIC program (or several BASIC programs, but they must coexist in the same line number space.) Personally, I find the lack of integration between the BASIC computer and calculator personalities a serious drawback in these types of machines.

As usual, I wrote a Gamma function program to test the capabilities of this machine. This variant uses the modified version of Stirling's formula to compute the logarithm of the Gamma function:

30:IF X>5 THEN 70
60:GOTO 30
70:G=X*LN X-X-LN G+LN √(2*π/X)