The TI-81 was the first

graphing calculator Graphing Calculator may refer to: * Graphing calculators, calculators that are able to display and/or analyze mathematical function graphs * NuCalc, a computer software program able to perform many graphing calculator functions * Grapher, th ...

made by

Texas Instruments Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartered in Dallas, Texas. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog ...

. It was designed in 1990 for use in

algebra Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic ope ...

and

precalculus In mathematics education, precalculus is a course, or a set of courses, that includes algebra and trigonometry at a level that is designed to prepare students for the study of calculus, thus the name precalculus. Schools often distinguish betwe ...

courses. Since its release, it has been superseded by a series of newer calculators: the TI-85, TI-82, TI-83, TI-86, TI-83 Plus, TI-83 Plus Silver Edition, TI-84 Plus, TI-84 Plus Silver Edition, TI-84 Plus C Silver Edition,

TI-Nspire The TI-Nspire is a graphing calculator line made by Texas Instruments, with the first version released on 25 September 2007. The calculators feature a non-QWERTY keyboard and a different key-by-key layout than Texas Instruments's previous ...

, TI-Nspire CAS, TI-84 Plus CE, and most recently, the TI-84 Plus CE Python. Most of them 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 graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...

display that began with this calculator, with the exceptions of the TI-84 Plus C Silver Edition and the TI-84 Plus CE family.

Features

The TI-81 is powered by a

Zilog Z80 The Zilog Z80 is an 8-bit computing, 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be Backward compatibility, software-compatible with the ...

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

, like those used in almost every other Texas Instruments graphing calculator (except the TI-80,

TI-89 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 algebra ...

, TI-89 Titanium, TI-92, TI-92 Plus, Voyage 200 and

series). However, the processor is clocked at 2

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

whereas the other Z80-powered Texas Instruments calculators run at speeds of at least 6

(the TI-83 Plus Silver Edition, TI-84 Plus, and TI-84 Plus Silver Edition can run at 15

). 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 un ...

s of user

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

, 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 , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

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 DOS or

DOSBox DOSBox is a free and open-source MS-DOS emulator. It supports running programs primarily video games that are otherwise inaccessible since hardware for running a compatible disk operating system (DOS) is obsolete and generally unavailab ...

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