Калькуляторы TI-83: История и Модели Серии

Series of graphing calculators produced by Texas Instruments

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 addition to the functions present on normal scientific calculators, the TI 83 includes many features, including function graphing, polar/parametric/sequence graphing modes, statistics, trigonometric, and algebraic functions, along with many useful applications. Although it does not include as many calculus functions, applications and programs can be written on the calculator or loaded from external sources. The TI 83 was redesigned twice, first in 1999 and again in 2001. TI replaced the TI 83 with the TI 83 Plus in 1999. The 2001 redesign introduced a design very similar to the TI 73 and TI 83 Plus, eliminating the sloped screen that had been common on TI graphing calculators since the TI 81. Beginning with the 1999 release of the TI 83 Plus, it has included Flash memory, enabling the device's operating system to be updated if needed, or for large new Flash Applications to be stored, accessible through a new Apps key. The Flash memory can also be used to store user programs and data. In 2001, the TI 83 Plus Silver Edition was released, which featured approximately nine times the available flash memory, and over twice the processing speed (15 MHz) of a standard TI 83 Plus, all in a translucent grey case inlaid with small "sparkles". The 2001 redesign (nicknamed the TI 83 "Parcus") introduced a slightly different shape to the calculator itself, eliminated the glossy grey screen border, and reduced cost by streamlining the printed circuit board to four units.

The TI 83 Plus was designed in 1999 as an upgrade to the TI 83. The TI 83 Plus is one of TI's most popular calculators. It uses a Zilog Z80 microprocessor running at 6 MHz, a 96×64 monochrome LCD screen, and 4 AAA batteries as well as backup CR1616 or CR1620 battery. A link port is also built into the calculator in the form of a 2.5 mm jack. The main improvement over the TI 83, however, is the addition of 512 KB of Flash ROM, which allows for operating system upgrades and applications to be installed. Most of the Flash memory is used by the operating system, with 160 KB available for user files and applications. Another development is the ability to install Flash Applications, which allows the user to add functionality to the calculator. Such applications have been made for math and science, text editing (both uppercase and lowercase letters), organizers and day planners, editing spread sheets, games, and many other uses. Designed for use by high school and college students, though now used by middle school students in some public school systems, it contains all the features of a scientific calculator as well as function, parametric, polar, and sequential graphing capabilities; an environment for financial calculations; matrix operations; on calculator programming; and more. Symbolic manipulation (differentiation, algebra) is not built into the TI 83 Plus. It can be programmed using a language called TI BASIC, which is similar to the BASIC computer language. Programming may also be done in TI Assembly, made up of Z80 assembly and a collection of TI provided system calls. Assembly programs run much faster, but are more difficult to write. Thus, the writing of Assembly programs is often done on a computer.

The TI 83 Plus Silver Edition was released in 2001. Its enhancements are 1.5 MB of flash memory, a dual speed 6/15 MHz processor, 96 KB of additional RAM (but TI has yet to code support for the entire RAM into an OS), an improved link transfer hardware, a translucent silver case, and more applications preinstalled. This substantial Flash memory increase is significant. Whereas the TI 83+ can only hold a maximum of 10 apps (or more often less, dependent on size), the Silver Edition can hold up to 94 apps. It also includes a USB link cable in the box. It is almost completely compatible with the TI 83 Plus; the only problems that may arise are with programs (e. g. games) that may run too quickly on the Silver Edition or with some programs which have problems with the link hardware. The key layout is the same. A second version of the TI 83 Plus Silver Edition exists, the ViewScreen (VSC) version. It is virtually identical, but has an additional port at the screen end of the rear of the unit, enabling displays on overhead projectors via a cable and panel. It looks similar to the standard TI 83 Plus, but has a silver colored frame, identical to the standard Silver Edition, around the screen. The TI 83 Plus Silver Edition is listed on the Texas Instruments website as "discontinued." In April 2004, the TI 83 Plus Silver Edition was replaced by the TI 84 Plus Silver Edition. They feature the same processor and the same amount of Flash memory, but the TI 84 Plus Silver Edition features a built in USB port, clock, and changeable faceplates.

The TI 83 Plus series are very similar in the languages natively supported by the calculator. These include "TI BASIC", an interpreted language used by all of TI's calculators, and "TI ASM", an unofficial name for the native Z80 assembly language on which the calculator is based.

TI continued to rely on RSA cryptographic signing keys only 512 bits long for many years after it was known that longer keys were necessary for security. 512 bit keys had been publicly cracked in 1999 as part of the RSA Factoring Challenge. In 2009, a group of enthusiasts used brute force and distributed methods to find all of the cryptographic signing keys for the TI calculator firmware, allowing users to directly flash their own operating systems to the devices. The key for the TI 83+ calculator was first published by someone at the unitedti. org forum. They needed several months to crack it. The other keys were found after a few weeks by the unitedti. org community through a distributed computing project. Texas Instruments then began sending out DMCA take down requests to a variety of different websites mirroring the keys, including unitedTI and reddit. com. They then became subject to the Streisand effect and were mirrored on a number of different sites.

The TI 84 Plus series was introduced in April 2004 as a further update to the TI 83 Plus line. Despite the new appearance, there are very few actual changes. The main improvements of the TI 84 Plus and TI 84 Plus Silver Edition are a modernized case design, changeable faceplates (Silver Edition only), a few new functions, more speed and memory, a clock, and USB port connectivity. The TI 84 Plus also has a brighter screen with a clearer contrast, though this caused a bug with the LCD driver in some calculators sold. The TI 84 Plus has 3 times the memory of the TI 83 Plus, and the TI 84 Plus Silver Edition has 9 times the memory of the TI 83 Plus. They both have 2.5 times the speed of the TI 83 Plus. The operating system and math functionality remain essentially the same, as does the standard link port for connecting with the rest of the TI calculator series. While mobile devices and the internet have superseded any calculator's capabilities, standardized testing precludes the use of those devices. Furthermore, textbooks have been tailored for the TI 83 effectively giving the calculator a "monopoly in the field of high school mathematics."