Texas Instruments TI-57 LCD

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Texas Instruments has been manufacturing the highly successful entry-level TI-55 and the semi-professional TI-57 programmable scientific calculators since 1977. With the success of low-power liquid crystal displays (LCDs), it has become possible to reduce the calculator’s energy consumption by up to a thousandth using only two button cells. The first, simpler models appeared in the company's product range from 1978, but production of the programmable versions began only in 1981.

Designed to be the successor to the TI-55, the TI-55-II has much more functions: signum, integer, fraction, and absolute values, combinatorial calculations, and easier programmability.

The only setback was the memory: when allocating (partitioning) the memory to storage registers and program area, the maximal available 56 steps cost almost all storage registers, only one can be used. Overall, at a given program length, the new model has fewer memory registers by two than its predecessor.

Unfortunately, the TI-57 was not so successful: because the TI-57 LCD was created by modification of the TI-55-II, much of the program stored in the ROM was sacrificed to implement the more advanced programming model: the statistical calculations were completely gone, and only the most necessary scientific functions remained. Due to the limited RAM capacity, one of the 8 memory registers available was reserved for the t-register, but the other 7 were only available if programming was abandoned. By exchanging one memory register for 8 program steps, the calculator’s maximal program length was 48 steps (with only one storage register).

Manufactured from 1982 onwards, the TI-57 LCD, like the machines of the era, is made with the classic Klixon keyboard, but due to incorrect material selection, the quality of the machines deteriorated steadily, while in 1984 the manufacturer decided that — as with the basic machines —, the scientific models will be redesigned to use the reliable rubber membrane keyboard, which have been proven in Japanese calculators for many years. A portion of these two models (TI-55-III, TI-57-II), available since 1985, have been made in Taiwan due to further rationalization of production.

A small series of Italian TI-57 LCD in 1983-84, and TI-57-II in 1985 was assembled in Hungary at Híradástechnika Szövetkezet (Telecommunication Cooperative) and marketed under the original type designation, but with the label "Assembled in Hungary".