Texas Instruments TI-81
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 |
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Texas Instruments TI-81
The TI-81 is an earlier member of Texas Instrument's current graphic calculator family. It has 2400 bytes of user memory for storing programs and variables. Programming the TI-81 is very similar to programming Casio calculators. Even their limitations are very much alike: for instance, in the TI-81, just like on the Casio CFX-9800G, I have not found a way to use the results of a user program (not just a simple expression) for building a graph. (Then again, since I don't have a TI-81 manual, maybe I am just missing the obvious somewhere.) In any case, I'm wondering whether these similarities are merely a coincidence.
Here is what a program that calculates the Gamma function for any real argument looks like on the TI-81:
:Input X :1->Y :Lbl 1 :If X>=0 :Goto 2 :XY->Y :X+1->X :Goto 1 :Lbl 2 :e^(ln ((1+(76.18009172+9.5E-9)/(X+1) -86.50532033/(X+2)+24.01409824/(X+3) -1.231739572/(X+4)+1.208650973E-3/(X+5) -5.395239384E-6/(X+6))√(2π)/X) +(X+.5)ln (X+5.5)-X-5.5)/Y->Y :Disp Y