Calculator input methods

A Button-operated calculator is a hardware or software calculator which is operated using button - as oposed to a Formula calculator which is operated thrue entering formulars thue a keyboard.

Reverse Polish Notation (RPN)

Main article: Reverse Polish Notation

In Reverse Polish Notation also known as Postfix notation all operations are entered after the peratns on which the operatin is performed. Reverse Polish Notation is parenthesis-free which usualy leads to less button presses needed to perfom a operation. By the use of stack one can enter formulae withouth the need of rearange operands.

Examples

Formular	Key strokes	Key stroke count
${\displaystyle 1+2\times 3}$	1 ENTER 2 ENTER 3 × +	7
${\displaystyle \sin 30\times \cos 30}$	3 0 SIN 3 0 COS ×	7

Note example 1 which is one of the few examples where Reverse Polish Notation does not use the fewest button presses - provided one does not rearange operants. If one would do so then ony 5 key strokes would be needed.

infix logic

Examples

Formular	Key strokes	Key stroke count
${\displaystyle 1+2\times 3}$	2 × 3 + 1 =	6
${\displaystyle \sin 30\times \cos 30}$	3 0 SIN × 3 0 COS =	8

algebraic logic

Examples

Formular	Key strokes	Key stroke count
${\displaystyle 1+2\times 3}$	1 + 2 × 3 =	6
${\displaystyle \sin 30\times \cos 30}$	3 0 SIN × 3 0 COS =	8

BASIC notation

Main article: Pocket computer

In BASIC notation the formular is entered as it would be entered in BASIC PRINT command - the PRINT command itself beein optional. On pressing the ENTER the result would be displayed. Typing mistakes in the entered formular could be corrected using the same editor function as available when programming the calculator.

Some BASIC programmable Pocket computers had dedicated trigonometric keys ^[1] hance the keystroke count is given as a range.

Some BASIC programmable Pocket computers could also be operated in arithmetic logic.

Examples

Formular	Key strokes	Key stroke count
${\displaystyle 1+2\times 3}$	1 + 2 × 3 ENTER	6
${\displaystyle \sin 30\times \cos 30}$	SIN ( 3 0 ) × COS ( 3 0 ) ENTER	12 .. 16

Direct algebraic logic (D.A.L.)

Direct algebraic logic (D.A.L.) is a method for entering equations on scientific calculators which allows symbols and numbers to be entered as they are written. SHARP introduced it in 1992^[2]. Today D.A.L. is used almost with every scientific calculator except those which use Reverse Polish Notation.

Other known entry modes are Algebraic logic (A.L.) which was used in earlier calculators and BASIC notation which was used BASIC programmable Pocket computers. Both can be seen as ancestors to D.A.L.

Examples

Formular	Key strokes	Key stroke count
${\displaystyle 1+2\times 3}$	1 + 2 × 3 ENTER	6
${\displaystyle \sin 30\times \cos 30}$	SIN 3 0 → × COS 3 0 ENTER	9

Note the → in the 2nd example: most DAL calculators will automatically insert needed parenthesis and the → key skips over the closing parenthesis from the sin operation. Machines equipped with an alphanumeric display will display SIN(30)×COS(30) before pressing ENTER.

References

1. The picture of the FX-880P show sin, cos and tan keys on the second row right hand side.
2. D.A.L description from Sharp

External links