Solar power & lithium battery (LR44)
Weight: 102 g (136 g with cover)
Dimensions (with cover) :
width: 80 mm (86 mm)
length: 168 mm (171 mm)
height: 16 mm (18 mm)
[ EL-W516XBSL, pictured at left ]
47 + 4 keys
dot-matrix LCD (96 by 31 pixels)
4 lines of 16 characters
(5 by 7 font) or 2D layout
15-digit precision
(10 digits shown)
9 variables: x,y,m,a,b,c,d,e,f
4 formula memories: f1,f2,f3,f4
556 functions
4 user-definable keys
list price: $25
street price: $18
(2013-11-02) Sharp's line of scientific calculators. Model numbers.
An EL-W516XBSL is an EL-W516x and little more than an EL-W516.
In Sharp's product line, "EL-" denotes handheld calculators.
A "W" prefix before the model number indicates WriteView capabilities,
which is Sharp's lingo for a dot-matrix screen capable of displaying
up to 4 lines of text or a 2D layout for input and output of mathematical expressions.
This type of capability is heralded as
Natural Textbook Display or
VPAM (visually perfect algebraic method) by Casio,
MultiView by TI
and SmartCalc by HP.
It's also described generically as "textbook" or simply "4-line".
Sharp also sells 2-line models, like the EL-506X (440 functions) or EL-546,
which are otherwise similar to the model reviewed here.
Sharp's line of WriteView calculators (i.e., dot-matrix screen) includes a
nice sturdy discontinued style previously sold either as
EL-W506 or
EL-W516
and a slimmer design sold as EL-W516x (556 functions) used for this review,
presenting little or no functional improvement over its predecessor.
Sharp may sell its calculators in different colors and designs
identified by suffix letters like B (black), W (white) or BSL (black slimline)
independent of the calculator's functionality.
For example, the above picture shows a calculator which can be ordered as EL-W516XBSL
but it rightly shows EL-W516X on its faceplate to advertise its internals
(if you hold the calculator, you don't have to be told that it's black or what its shape is).
This naming scheme confuses some online purchasers.
(2013-10-31) Basic keys and modifiers (no multi-taps )
Most keys have more than one use.
To restore the calculator to factory settings, gently shove the tip of a pen into the "reset" hole
located in the back of the unit.
In the top-left corner of its keypad,
the calculator has two modifier keys which change the meaning of whatever key is pressed
after them. One is labeled "2nd F", in orange, and the other is labeled "ALPHA", in blue.
Those colors are used on the faceplate above a key to indicate whatever function it
corresponds to with the color-matched modifier key.
The "RCL", "STO" and "hyp" keys also function as modifiers or prefixer for just a few keys.
The last of these can itself be prefixed by the orange modifier to obtain the inverse
of hyperbolic functions...
To turn on the calculator, you push the "ON/C" key which also serves
to cancel the current action during normal operation of the calculator.
That same button turns the calculator off if used after the aforementioned orange modifier key.
All this is pretty standard.
Sharp also allows cancellation of input data
on a character-by-character basis.
The standard way to do this is to erase the character before the input cursor
(which is usually the last character typed).
On the EL-w516x, this is done by pushing the key marked "BS" (for back-space )
located below the top-right "ON/C" key, one spot down.
There's also the lesser-used possibility of erasing the character on which the cursor stands.
This is the secondary function of that same key, obtained by prefixing it with the
orange modifier key. Sharp call it "DEL" (for delete )
which is the term often used by other manufacturers for the more common backspacing just described.
On my "black slimline" (BSL) machine (purchased in October 2013) Sharp uses a deep shade of blue
for the labelling related to the second modifier key.
The primary labels of most keys are printed either in bright white (for the 19 basic
functions in the lower half of the keypad) or in grey for a less agressive
look on the upper part of the keypad. If your eyes are more than fifty years old,
you may not be impressed by the latter.
Sharp had the pedagological idea to use blue for the primary labels of two keys
(STO and RCL)
which are always used to prefix an "alphabetic" reference to a variable (thus making the use of
"ALPHA" optional).
Unfortunately, they spoiled that nice touch by using blue for the M+ key also
(which isn't a prefixer at all).
The calculator offers a total of 9
named variables (x,y,M,A,B,C,D,E,F)
in which to store values (STO) to be recalled later (RCL).
One of these (M) can be modified be adding to it or subtracting
from it in one step, using the M+ and M- keys, in a way familiar to users of
non-scientific calculators...
The names of standard functions always precedes and opening parenthesis.
Unlike some other calculator manufacturers, Sharp doesn't provide this
patenthesis "free of charge"... The user always has to type
both of the opening and closing parentheses.
User-definable Keys: D1, D2, D3, D4
Any predefined function can be assigned to one of those four keys.
This is just a convenience to quickly access repeatedly a function which
would otherwise require several key punches...
For example, the ANS function, which stands for the value of the last result
returned. can be assigned to the D1 key (it normally requires two
keystrokes; the ALPHA prefix followed by the "=" key).
To do that, simply type the following, once and for all:
[STO] [D1] [ALPHA] [=]
In the 1970's HP applied this basic idea of recording keystrokes and playing them back
to turn its earlier RPN scientific calculators into programmable ones.
This was made possible by the fact that the RPN philosophy allows
operations to be chained effortlessly...
The EL-W516 isn't an RPN calculator and it can't be made programmable this way.
(2013-11-02) Entering and exiting specialized modes:
For better or for worse, the EL-W516 is a multimode calculator.
To go back to the normal mode of ordinary calculations with real numbers after venturing into
any other mode, press the MODE key (top-right, below the "ON/C" key)
followed by the "0" key
(a less powerfull escape alternative is the cancel
operation, obtained by punching the orange key followed by MODE).
To enter a specialized mode, press [MODE] to view a screen showing 6 possible choices numbered
from 0 to 5. There's another screenful, accessible with the downward navigation key
which gives a 7th choice (numbered 6) corresponding to the equation
solver. You may select a number even if it's not displayed on the current
screen.
(Sharp could have displayed all modes on a single screenful if they hadn't chosen
to waste the top line on a useless title. Small mistake there.)
(2013-11-02) MODE 6: Equation solver.
Cubic equations can be solved easily.
Unfortunately, the calculator doesn't properly handles multiple roots.
For example, try to solve this equation:
x3 + x2
- 8 x
- 12 = 0
To do that, you punch in [MODE] [6] [3] to bring up the screen for cubic equations
and input the proper values of the a,b,c,d coefficients by typing:
[1] [=] [1] [=] [(-)] [8] [=] [(-)] [1] [2] [=]
Without the bug, that would give you the following screenful:
X=
1: 3.
2: -2.
3: -2.
Instead, the last line is omitted by the calculator
(in a misguided effort to "simplify" things).
So, you've no way to tell which of the two roots
(3 or -2) is a double one.
According to the fundamental theorem of algebra,
a cubic polynomial always has three roots, real or complex, distinct or not.
It would be nice if an educational calculator stressed that point correctly.
