Engineering notation: Difference between revisions

Revision as of 13:06, 3 February 2021

Revision as of 12:01, 26 April 2021

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Based on an idea by Peter D. Dickinson<ref name="Dickinson_1976"/><ref name="Gordon_1969"/> the first [[calculator]] to support engineering notation displaying the power-of-ten exponent values was the [[HP-25]] in 1975.<ref name="Neff_1975"/> It was implemented as a dedicated display mode in addition to scientific notation.

In 1975 [[Commodore Business Machines|Commodore]] introduced a number of scientific calculators (like the [[Commodore SR4148|SR4148]]/SR4148R<ref name="Commodore_SR4148R"/> and [[Commodore SR4190R|SR4190R]]<ref name="Commodore_SR4190R"/>) providing a ''variable scientific notation'', where pressing the {{button|EE↓}} and {{button|EE↑}} keys shifted the exponent and decimal point by ±1<ref group="nb" name="NB_Exp-Shift"/> in ''scientific''<!-- not engineering! --> notation. Between 1976 and 1980 the same ''exponent shift'' facility was also available on some [[Texas Instruments]] calculators of the pre-[[LCD]] era such as early [[TI SR-40|SR-40]],<ref name="SR-40"/><ref name="SR-40_Manual"/> [[TI-30]]<ref name="TI-30"/><ref name="TI-30_Manual"/><ref name="TI-30-BR"/><ref name="TI-30_BR_Manual"/><ref name="TI-30_2"/><ref name="TI-30_RCI"/><ref name="TI-30_1"/><ref name="TI-30_Super"/> and [[TI-45]]<ref name="TI-45"/><ref name="TI-45_Manual"/> model variants utilizing ({{button|INV}}){{button|EE↓}} instead. This can be seen as a precursor to a feature implemented on many [[Casio]] calculators since 1978−791978/1979 (e.g. in the [[Casio FX-501P|FX-501P]]/[[Casio FX-502P|FX-502P]]), where number display in ''engineering'' notation is available on demand by the single press of a ({{button|INV}}){{button|ENG}} button (instead of having to activate a dedicated display mode as on most other calculators), and subsequent button presses would shift the exponent and decimal point of the number displayed by ±3<ref group="nb" name="NB_Exp-Shift"/> in order to easily let results match a desired prefix. Some graphical calculators (for example the [[Casio fx-9860G|fx-9860G]]) in the 2000s also support the display of some SI prefixes (f, p, n, μ, m, k, M, G, T, P, E) as suffixes in engineering mode.

==Overview==