Calculator input methods

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^[1]. 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.

Example: ${\displaystyle \sin 30\times \cos 30}$

with reverse polish notation

3 0 SIN 3 0 COS ×

with algebraic logic

3 0 SIN × 3 0 COS =

with BASIC notation

SIN ( 3 0 ) × COS ( 3 0 ) ENTER

with direct algebraic logic

SIN 3 0 → × COS 3 0 ENTER

Note 1: the →: most DAL calculators will automatically insert needed ( ) and the → skips over the ) from the sin operation. Machines equipped with an alphanumeric display will display SIN(30)×COS(30) before pressing ENTER. Note 2: Some but not all BASIC programmable Pocket computers had dedicated trigonometric keys ^[2].

Criticism

As seen in the example above the increased need for ( and ) results in a larger number of key presses to enter a formula. In the example above: D.A.L. 9 key presses, BASIC: 12 .. 16 key presses, A.L.: 8 key presses, RPN: 7 key presses.

References

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

External links