Citizen SRP-265

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: Numeric display  
New price:   Display color: Black  
    Display technology: Liquid crystal display 
Size: 6"×3"×½" Display size: 10(8+2) digits
Weight: 4 oz    
    Entry method: Algebraic with precedence 
Batteries: 2×"LR44" button cell Advanced functions: Trig Exp Hyp Sdev Cmem Const 
External power:   Memory functions:
I/O:      
    Programming model: Partially merged keystroke 
Precision: 12 digits Program functions:  
Memories: 3 numbers Program display:  
Program memory: 40 program steps Program editing:  
Chipset:   Forensic result: 9.0000278599  

Citizen SRP-265The Citizen SRP-265 is a fine scientific calculator even if it is a somewhat boring one: a plain scientific machine with 40 program steps, no branching or conditionals, and only a standard set of scientific functions.

For me, however, this calculator is special. In this case, the reason is not sentimental: not some fond memory from 25 years ago when I was trying to decide what was more important, programmable calculators or members of the opposite sex. No, the SRP-265 is special because it happens to be the very first calculator for which I implemented the automatic generation of a Web page. You see, much of the page you're reading right now, in fact the entire top part (the "Datasheet") is now machine-generated from a fine MySQL database. If I find that it works reliably, all other calculator pages will be similarly updated in the near future.

As for the SRP-265, there's not much more to say. It is hard to write an exciting description about a machine that, despite its elegant appearance, is really just a boring standard scientific calculator with minimal programmability. Instead, here's a simple implementation of the Gamma function using Stirling's approximation to demonstrate this machine's programming model:

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