National Semiconductor 4515 Mathematician PR
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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 |
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National Semiconductor 4515 Mathematician PR
When I first read about the Novus Mathematician PR, I began to wonder: what makes this calculator different from its close relative, the Novus Scientist PR? They seem to have nearly identical functionality, at least judging by their keyboards alone.
When I finally got my hands on one of these machines, I had my answer: imagine a calculator with a full complement of scientific functions that cannot display numbers in scientific notation! What the...
It is also an RPN calculator like the Scientist PR, but apparently, it only has a three-level stack, and no stack roll function. Sometimes it really makes me wonder, just what were these designers thinking!
There is one area in which the Mathematician PR is a little better than the Scientist PR: its mathematical algorithms are more accurate. For instance, 1 arc tan actually yields a result of 45, instead of 45.000654 like on the Scientist PR...
With this machine's crippled RPN model, the polynomial approximation of the Gamma function, my favorite programming example, is a no go. But an enhanced version of Stirling's formula can be written easily, yielding at least 5 digits of accuracy for arguments 2 and above. For instance, 5 start yields 24.00004 after exponentiation, which is pretty darn close to the correct result, 24.
MS EN ln × MR - 2 π × MR ÷ ln 2 ÷ + 1 2 1/x MR ÷ + 4 0 0 1/x MR ÷ MR ÷ MR ÷ -
