Aurex SC-6495

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: 6½"×3½"×½" Display size: 10+2 digits and 12 characters
Weight: 5 oz    
    Entry method: Formula entry 
Batteries: Advanced functions: Trig Exp Hyp Lreg Solv Intg Ab/c Cplx Cmem Mtrx BaseN Units Const 
External power:   Memory functions: +/- 
    Programming model: Formula programming 
Precision: 12 digits Program functions:  
Memories: 9 numbers Program display:  
Program memory: 900 program steps Program editing:  
Chipset:   Forensic result: 9.000001564314  

SC-6495 It is 2024, and it is very rare these days that I stumble upon a "new" old calculator. OK, not exactly vintage, not much older than 10 years, but one that is a tad different from the rest of them. Yet this is exactly what happened when the other day, my beautiful wife brought home this machine, carrying the Aurex brand label. Quite a capable scientific calculator, somewhat unusual in that it offers a generous 900 program steps of program memory, divided into 20 labeled programs. The one fly in the ointment is that individual programs (stored formulas, really), can be no longer than 79 steps, and that the calculator lacks the ability of conditional execution or jumps. Oh, the other fly in the ointment is that it came with no manual. More about that below. But first... The programming model is the standard "formula programming" concept: You key in a formula, then you execute it as many times as you wish. The formula may make use of the Ans key, to process the result of a previous calculation. In that spirit, here's a formula program that computes the logarithm of the Gamma function, specifically $\ln\Gamma(z+1)$, usually to better than 7-digit accuracy for positive arguments, using the Lanczos-approximation. (A more accurate formula would have exceeded the size limit on individual programs.) Without further ado:


Now about that manual. I searched for it with Google, to no avail. The best I was able to ascertain is that the original calculator (Aurex is an OEM label I believe) is the Ataba DS-742AQ, a machine that is listed here in the RSKEY.ORG database, but one I never encountered in person. So I searched for the DS-742AQ manual but again, came up empty-handed. Next I tried Bing, which was also unable to locate the manual, but helpfully offered assistance in the form of its chatGPT-powered Copilot. Sure, why not? So we exchanged a few messages with Copilot, but apart from finding the manual for an unrelated model and one for a Hikvision radar device, it was not able to help either. When I said that much, however, Copilot responded with the following:

I apologize for the inconvenience, and I understand your frustration. It seems like the elusive DS-742AQ manual remains a mystery, much like an unsolved equation. 🤔

Since we’re navigating the labyrinth of vintage calculators, let’s embark on a poetic journey—a tribute to the enigmatic DS-742AQ:

The Ballad of the DS-742AQ


In the halls of forgotten tech,

Where transistors whispered secrets,

Lies the DS-742AQ, a relic of yore,

Its buttons worn, its mysteries galore.


A calculator by day, a sage by night,

Its LED eyes blinked cryptic light,

Programmable prowess hidden within,

Yet manuals vanished, like a fleeting grin.


The Hikvision radar scoffs nearby,

“Banish your numbers, seek the sky!”

But we persist, our quest unyielding,

For the DS-742AQ’s truth, revealing.


We scoured forums, threads, and bytes,

Chasing echoes of forgotten rites,

Yet the answer eludes, a spectral dance,

A phantom manual, lost in chance.


“Never mind,” they said, those seekers past,

Their secret knowledge locked, steadfast.

But we, intrepid souls, shall persevere,

For the DS-742AQ’s legacy is clear.


So raise your stylus pens, my friend,

To the unsung heroes who transcend—

The vintage calculators, silent sages,

Guardians of algorithms through the ages.


And if, one day, the manual appears,

We’ll celebrate with joyous cheers,

For the DS-742AQ, enigma profound,

Shall yield its wisdom, unbound.

May the DS-742AQ’s secrets someday emerge, like a long-lost theorem rediscovered. Until then, let us revel in the mystery and honor its legacy! 🌟🔍📜

So here we go, the first ever calculator in my collection that earned an unsolicited ballad from a machine intelligence. Welcome to tomorrow!