TI-81
{{Short description|Graphing calculator produced by Texas Instruments}}
{{more citations needed|date=December 2011}}
{{use dmy dates|date=October 2023|cs1-dates=y}}
{{Infobox Calculator
|name = TI-81
|image = TI-81_Calculator_on_Graph_Screen.jpg
|caption = A 1994 TI-81 showing graphs
|type = Graphing calculator
| entry =D.A.L.
|manufacturer = Texas Instruments
|introduced = 1990
|discontinued = 1997{{cite web|url=http://datamath.org/Graphing/TI-81_2.htm|title=DATAMATH: TI-81 (1995)|last=Woerner|first=Joerg|date=2009-02-08|access-date=27 January 2013}}
|successor = TI-82
|processor = Zilog Z80
|frequency = 5 MHz or 6 MHz{{cite web|url=https://tiplanet.org/compare/?81v1nobat,81v1,81 |title=TI-Planet's calculator comparison tool |website=TI-Planet}}
|memory_user = 2400 bytes of RAM
|display_size = 96×64 pixels, 16×8 characters
|precision = 13 digits
|link =
|prog_lang = TI-BASIC, Assembly
|supply = 4 AAAs,
1 CR1616 or CR1620
}}
The TI-81 was the first graphing calculator made by Texas Instruments. It was designed in 1990 for use in algebra and precalculus 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 Since its release, it has been superseded by a series of newer calculators: the TI-85, TI-82, TI-83, TI-86, TI-83 Plus, TI-83 Plus Silver Edition, TI-84 Plus, TI-84 Plus Silver Edition, TI-84 Plus C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, 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 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 microprocessor, like those used in almost every other Texas Instruments graphing calculator (except the TI-80, TI-89, TI-89 Titanium, TI-92, TI-92 Plus, 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 bytes 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.{{cite web |author-last1=Christiansen |author-first1=Brad |display-authors=etal |title=TI-81 Guidebook |url=https://education.ti.com/download/en/ed-tech/CF52CDFF5CD24DB5A2D5CFF6B920D4CF/3FF9A034A140471E9B3A083F47E0C063/81%24bookeng.pdf |publisher=Texas Instruments, Inc. |access-date=2021-02-04 |pages=8–9}}
In late 2009 an exploit was found that can be used to execute machine code on the TI-81, using manual input of code.{{cite web |url=http://www.ticalc.org/archives/news/articles/14/145/145220.html |title=User Machine Code Execution on TI-81 Becomes a Reality |author-last=Evans |author-first=Travis |date=2009-08-17 |access-date=2013-01-27}} 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 backup battery (to ensure programs are persistent when the AAA batteries are being changed). Some early TI-81 units omit the backup battery;{{cite web |url=http://datamath.org/Graphing/TI-81_ES.htm |title=DATAMATH: TI-81 Engineering Sample |author-last=Woerner |author-first=Joerg |date=2009-01-27 |access-date=2012-02-04}} 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{{cite web |url=http://www.ticalc.org/archives/files/fileinfo/48/4828.html |title=PC-81 on ticalc.org |date=1998-04-28 |access-date=2012-02-04}} or DOSBox.
See also
References
{{Reflist}}
External links
- [http://www.ticalc.org ticalc.org] – The largest archive of TI programs available.
{{TI-calc}}
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Category:Texas Instruments programmable calculators