The TI-81 is the first graphing calculator made by Texas Instruments and was manufactured between 1990 and 1997. It features a 96 by 64 pixel LCD display, a 2 megahertz Zilog Z80 processor, and 2.4 kilobytes of memory for the user to store programs made in BASIC. Programs on the calculator have to be keyed in by hand due to the lack of a link port and the TI-81 has a very restrictive form of TI-BASIC and can only store four graph equations in memory.
The TI-81's design is very appealing for to the time period it was designed in. Texas Instruments was relatively late to the graphing calculator market with HP and Sharp entering much before them and Casio pioneering the industry with their fx-7000G, releasing as the first commercially available graphing calculator, in 1985. The design of the TI-81 is very much inspired by consumer electronics that were available during the late 80s making the design look much more up to date than, for example, the CFX-9850GB Plus which had a design very reminiscent of late 70s consumer electronics with its rugged design and stylised font used on the numeric keys. In comparison, the 81, while very simplistic and utilitarian, is able to still look elegant and capture the look of the time.
I own a single example of this calculator which is in working condition with the slide case.
This calculator is in good condition and works well. It is blue and was manufactured August 1992. It runs OS 1.8K and I obtained it November 13th, 2023. The buttons on this example feel very nice and it is a joy to use. I very much enjoy the Sony Watchman-like slanted screen.
Gallery of pictures for this calculator