The TI-81 was the first

graphing calculator A graphing calculator (also graphics calculator or graphic display calculator) is a handheld computer that is capable of plotting graphs, solving simultaneous equations, and performing other tasks with variables. Most popular graphing calculat ...

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 globall ...

. It was designed in 1990 for use in

algebra Algebra () is one of the 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 mathematics. Elementary a ...

and

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

courses. Since its original release, it has been superseded several times by newer calculators: the

TI-85 The TI-85 is a graphing calculator made by Texas Instruments based on the Zilog Z80 microprocessor. Designed in 1992 as TI's second graphing calculator (the first was the TI-81), it was replaced by the TI-86, which has also been discontinued ...

TI-82 The TI-82 is a graphing calculator made by Texas Instruments. The TI-82 was designed in 1993 as a stripped down, more user friendly version of the TI-85, and as a replacement for the TI-81. It was the direct predecessor of the TI-83. It shares ...

, TI-83,

TI-86 The TI-86 is a programmable graphing calculator introduced in 1996 which was produced by Texas Instruments. The TI-86 uses the Zilog Z80 microprocessor. It is partially backwards-compatible with its predecessor, the TI-85. In addition to ha ...

TI-83 Plus The TI-83 series is a series of graphing calculators manufactured by Texas Instruments. The original TI-83 is itself an upgraded version of the TI-82. Released in 1996, it was one of the most popular graphing calculators for students. In additio ...

TI-83 Plus Silver Edition The TI-83 series is a series of graphing calculators manufactured by Texas Instruments. The original TI-83 is itself an upgraded version of the TI-82. Released in 1996, it was one of the most popular graphing calculators for students. In additio ...

TI-84 Plus The TI-84 Plus is a graphing calculator made by Texas Instruments which was released in early 2004. There is no original TI-84, only the TI-84 Plus, the TI-84 Plus Silver Edition models, and the TI-84 Plus CE. The TI-84 Plus is an enhanced ve ...

TI-84 Plus Silver Edition The TI-84 Plus is a graphing calculator made by Texas Instruments which was released in early 2004. There is no original TI-84, only the TI-84 Plus, the TI-84 Plus Silver Edition models, and the TI-84 Plus CE. The TI-84 Plus is an enhanced ve ...

, and most recently the

TI-Nspire The TI-Nspire is a graphing calculator made by Texas Instruments, which was released in July 2007, notable for featuring a non-QWERTY keyboard and a different key-by-key layout than its predecessors. Development The original 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 smal ...

display that began with this calculator.

Features

The TI-81 is powered by a

Zilog Z80 The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples wer ...

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 level (grades 6-8). The TI-80 featured a 48 x 64 dot-matrix display with a 5 x 3 pixel font, which is the smallest scre ...

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 algeb ...

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 algeb ...

TI-92 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 ...

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 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 ...

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), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

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

(the

, and

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 unit ...

s of user

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * ...

, 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 The AAA battery (or triple-A battery) is a standard size of dry cell battery. One or more AAA batteries are commonly used in low-drain portable electronic devices. A zinc–carbon battery in this size is designated by IEC as R03, by ANSI C18.1 ...

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 el ...

backup

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

(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 DOSBox is a free and open-source emulator which runs software for MS-DOS compatible disk operating systems—primarily video games. It was first released in 2002, when DOS technology was becoming obsolete. Its adoption for running DOS games i ...

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