The TI-81 was the first graphing calculator released by

Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...

. It was designed in 1990 for use in

algebra Algebra () is one of the areas of mathematics, broad areas of mathematics. Roughly speaking, algebra is the study of mathematical symbols and the rules for manipulating these symbols in formulas; it is a unifying thread of almost all of mathem ...

and precalculus courses. Since its original release, it has been superseded several times by newer calculators: the TI-85, TI-82, TI-83, TI-86, TI-83 Plus, TI-83 Plus Silver Edition, TI-84 Plus, TI-84 Plus Silver Edition, and most recently the TI-Nspire and TI-Nspire CAS. Most of these share the original feature set and 96×64-

pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the s ...

display that began with this calculator.

Features

The TI-81 is powered by a Zilog Z80

microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...

, like those used in almost every other Texas Instruments graphing calculator (except the

TI-80 The TI-80 is a graphing calculator made by Texas Instruments. It was originally designed in 1995 to be used at a middle school A middle school (also known as intermediate school, junior high school, junior secondary school, or lower secondary ...

, TI-89,

TI-89 Titanium The TI-89 and the TI-89 Titanium are graphing calculators developed by Texas Instruments (TI). They are differentiated from most other TI graphing calculators by their computer algebra system, which allows symbolic manipulation of al ...

, TI-92,

TI-92 Plus The TI-92 series of graphing calculators are a line of calculators produced by Texas Instruments. They include: the TI-92 (1995), the TI-92 II (1996), the TI-92 Plus (1998, 1999) and the Voyage 200 (2002). The design of these relatively large ...

, Voyage 200 and TI-Nspire series). However, the processor is clocked at 2 MHz whereas the other Z80-powered Texas Instruments calculators run at speeds of at least 6 MHz (the TI-83 Plus Silver Edition, TI-84 Plus, and TI-84 Plus Silver Edition can run at 15 MHz). It contains 2400

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

s of user RAM, with additional RAM used internally by the calculator firmware software system. The TI-81's user interactions are provided by its so-called Equation Operation System. This is comparable to the interface provided by the more recent TI-82, TI-83, and so on. This system is capable of such tasks as two-dimensional parametric graphing (in addition to standard two-dimensional function graphing), trigonometric calculations in units of either degrees or radians, simple drawing capabilities, creation and manipulation of matrices up to 6x6 in size, and programming in a proprietary statement-based language. In late 2009 an exploit was found that can be used to execute machine code on the TI-81, using manual input of code. The TI-81 has no data link interface; its only means of input and output are the keyboard and screen. As with its successors, the TI-81 is powered by four AAA batteries and one CR1616 or CR1620

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

backup battery (to ensure programs are persistent when the AAA batteries are being changed). Some early TI-81 units omit the backup battery; if the AAA batteries of one of these units are changed one at a time and quickly, the memory contents are still retained. Texas Instruments distributes software which emulates the TI-81 and its Equation Operating System on a desktop computer using MS-DOS or DOSBox.

References

External links

ticalc.org
– The largest archive of TI programs available. {{Authority control Graphing calculators Texas Instruments programmable calculators Products introduced in 1990 Z80

Features

See also

References

External links