Texas Instruments TI-74
| 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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*Peripherals include the PC-324 printer and the CI-7 cassette interface cable.
Texas Instruments TI-74
The Texas Instruments TI-74 is a close relative to TI's earlier BASIC language programmable calculator, the Compact Computer-40. It is a quite capable handheld computer with an innovative feature: in "calculator mode", it operated like a conventional algebraic calculator with postfix and infix operators. (That is, in this mode, you'd type 5 + 3 = to obtain a result of 8, or 30 sin to obtain the result of 0.5.) This mode even offers ten numbered registers! This calculator mode addresses many of the shortcomings (well, I think they're shortcomings) that are a result of using a programming language like BASIC as the primary language interface of a handheld device.
The TI-74 has a peripheral port through which dedicated peripherals, such as a printer or cassette recorder interface, can be attached.
The TI-74 has an interesting variant: an OEM version called the TI-74S. Until I got my hands on one by accident (I thought I was buying a TI-74) I didn't know such a model even existed! This, obviously, is a customizable version of the TI-74 (the "Custom Program" label on the plastic shell case is a dead giveaway.) One characteristic of this version is that, just like on the "blanknut" versions of the HP-41, many of the keyboard labels are missing.
The similarity with the CC-40 is demonstrated by the fact that an identical implementation of the Gamma function works on both machines. Here is this example program again, for reference:
100 DATA 76.18009172947 110 DATA -86.50532032942 120 DATA 24.01409824083 130 DATA -1.23173957245 140 DATA 1.208650973866e-3 150 DATA -5.395239384953e-6 160 INPUT "X=? ";X 170 T=1 180 IF X>=0 THEN GOTO 220 190 T=T*X 200 X=X+1 210 GOTO 180 220 G=1.00000000019 230 FOR I=1 TO 6 240 READ P 250 G=G+P/(X+I) 260 NEXT 270 G=LN(SQR(2*PI)*G/X) 280 G=G-X-5.5+LN(X+5.5)*(X+.5) 290 PRINT "G(X)=";EXP(G)/T 300 PAUSE
