TI-33

TI-33 from 1977 in May 2019 -
after 42 years of defect-free use

The so-called "logarithm bug" in the sister model TI-30 - the value of ln (1.0000001) was calculated in each case

The TI-33 was a pocket calculator from Texas Instruments from 1977 that was widely used in schools . Compared to the simpler basic model TI-30 from the previous year, it was primarily equipped with three memory locations instead of just one and dispensed with a percent key. It was developed primarily for the European market and had no American counterpart.

Like the TI-30 , it had an LED display, which consumed more electricity than the later common liquid crystal displays (LCD or LC displays). Instead of a battery, however, it was sold with a rechargeable 9-volt block .

While the TMC0981 chip, developed and manufactured by Texas Instruments, was originally used in the TI-30, the TI-33 destined for Europe received the TMC0984, which was also produced by TI.

Functions

• 8/5 + 2-digit display
• Internal invoice with 11 + 2-digit number format
• Reciprocal (1 / x), square number (x²) and root (√)
• Trigonometric functions ( sine, cosine , tangent ) in degrees ( D EG), radians ( R AD) or gons ( G RAD) including arc functions ( arcsin, arccos , arctan )
• Tens - ( ) and natural ( ) logarithm ${\displaystyle \log }$ ${\displaystyle \ln }$
• Power function ${\displaystyle y^{x}}$
• Circle number key ( ) ${\displaystyle \pi \approx 3{,}141592653589793\ldots }$
• Automatic constants for the four basic arithmetic operations and the power function
• Three data storage keys (M1, M2, M3) with balance key
• AOS input (Texas Instruments Algebraic Operation System ) with consideration of the operator precedence , in addition:
• Bracket keys for max. 4 operations open at the same time

Calculation error

As in many TI calculators, the software in the TI-33 produces small calculation errors due to improperly designed numerical approximation methods, especially in transcendent functions such as logarithm .

Web links

Commons : TI-33  - collection of pictures, videos and audio files

• Texas Instruments TI-33 in the Datamath Calculator Museum ( English )
• Scientific school calculators - Germany at Texas Instruments

Individual evidence

1. ↑ ^{a b} Texas Instruments TI-33. datamath.org (Datamath Calculator Museum), accessed May 14, 2019 .  
2. ↑ Texas Instruments TI-30. datamath.org (Datamath Calculator Museum), accessed May 14, 2019 .