Spotlight: Sharp EL-520L
Quick Facts
Model: EL-520L
Company: Sharp
Type: Solar Scientific Algebraic
Power: Solar with battery backup, 2 x LR 44
Case: Slide case
Memory: 7 memory registers: A, B, C, D, X, Y, M (M has memory addition and subtraction)
Years in Production: 1998
Display: 2 line, with results up to 10 digits
Shout out to Spaceboy Jeffy’s Vintage Emporium from where I purchased the calculator.
Scientific Calculations in Two Lines
The Sharp EL-520L is an early two-line scientific calculator. The top line is where mathematical expressions are entered, where the bottom line is where the results are displayed.
Expressions are entered as written, as noted by Sharp’s ADVANCED D.A.L. (Direct Algebraic Logic.
Example (degrees mode, float mode):
(top | bottom)
0.5; Screen: DEG | 0.5
×; Screen: DEG 0.5*_ |
e^; Screen: DEG 0.5*e^_ |
(sin 10°); Screen: DEG 0.5*e^(sin10) |
=; Screen: DEG 0.5*e^(sin10)= | 0.594818475
Modes
The modes of the EL-520L are controlled by the MODE keys and two toggle keys:
Toggle keys:
[ DRG ]: Change mode through the degrees, radians, and grads cycle. This is how the angle mode is changed on scientific calculators from the 1980s.
[ 2ndF ] [ DRG ] ( DRG> ): A variation of angle change. In this variation, a conversion of angle measurement.
[ 2ndF ] [ . ] (FSE): This the display format toggle: Floating point (no indicator), fixed point (FIX), scientific notation (SCI), engineering notation (ENG). The TAB function, accessed by [ 2ndF ] [ +/- ], set the number of decimal points in the fixed point, scientific notation, and engineering notation format.
There is also a modify (MDF) function that internally rounds the result to the fixed decimal point settings. The modify function does not affect anything stored to variables, however. I wish there was a round function (Round(n, decimal points)) instead, to be honest.
The Mode Key:
The [ MODE ] key offers three modes:
0: Normal. Normal calculator mode.
1: STAT x: Single variable statistics. The [ STO ] key becomes the comma key and memory plus key [ M+ ] becomes the data entry key.
2: STAT xy: Linear regression mode. The data is fit to the equation y = a + bx where a is the y-intercept and b is the slope.
In the statistic modes, the variables (A -D, X, Y, M) are not operable.
Replay and Editing Keys
In Normal mode, there are three editing functions:
[ DEL ]: The standard delete character.
[ 2nd ] [ ← ] (⟲): Takes the cursor to the beginning of the last expression
[ 2nd ] [ → ] ( ? ): Takes the cursor to the next number after the cursor’s position
There is no insert/replace mode. It seems like Sharp was experimenting with editing commands.
Order of Operations (Quirks?)
In a lot of algebraic calculators, the square function has higher priority than negation. Entering -4² returns -16.
Implied multiplication gets a higher priority than division and regular multiplication. Therefore if we enter the infamous expression:
6÷2(1+2) returns 1 instead of 9.
This is known as PEJMDAS where J is juxtaposition, or implied multiplication. For more information, please see The How and Why of Mathematics’ video from 2019:
https://www.youtube.com/watch?v=4x-BcYCiKCk
I’ll leave the debate at this point. Of course, when it doubt, use extra parenthesis or insert an additional multiplication sign ( × ).
One quirk: To insert variables (A, B, C, D, X, Y, M) into expressions, press [ 2ndF ] [ RCL ] (ALPHA).
Final Thoughts
The Sharp EL-520L is nice, basic level calculator with the ability to enter expressions. The EL-520L has a nice amount of the features that will satisfy most needs.
Source
Flow Simulation, Ltd. “Sharp EL-520 (ADVANCED D.A.L.)” calculator.org https://www.calculator.org/calculators/Sharp_EL-520L.html
Eddie
All original content copyright, © 2011-2026. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
