Retro
Review: Casio fx85WA
I
want to give a special thank you to John Cadick. Cadick requested
that I review this calculator and has loaned me his calculator to
review. Much appreciated, and John, I hope you like this review.
General
Information
Company:
Casio
Type:
Scientific – Algebraic (Perfect
Algebraic Method)
Display:
10 digits with 2 digit exponents
Power:
Solar with
battery backup (LR44)
Memory
Registers:
8: A, B, C, D, E, F, X, Y ,M
Years:
Circa
19981999
Original
Cost: $10
to $20, depending on the store (at the time)
Documentation:
Manual, Quick
Reference card
Two
Line Display and Fractions
The
Casio fx85WA has a two line display: the top line for the
mathematical expression to be evaluated, and the bottom line displays
the answers. The font on the bottom line is bigger than the font on
the top line. Later models will have the fonts of both lines of
about equal size.
Screen for fx85WAS (left) and FX300MS (right) 
You
can enter equations as they are written, no need to worry about
postfix notation. The order of operations is effect for all
calculations.
You
can enter and do calculations with fractions with the [ a b/c ] key.
After a calculation is completed, the [ a b/c ] can convert results
between a fraction and decimal approximation. All fractions are
simplified. The maximum denominator is 9999. Conversions between
mixed fractions and improper fractions are also available.
The
functions available are:
*
Trigonometry: sine, cosine, tangent, with inverse and hyperbolic
*
Logarithmic: natural and common, with inverses
*
Square, square root, cube, and cube root (all primary key functions
on the fx85WA)
*
Reciprocal, factorial (calculating 69! on the fx85WS is surprising
slightly faster than later models)
*
Combination, permutation
*
Engineering notation with the [ENG] and its inverse
*
DegreeMinuteSeconds calculations [ ° ‘ “ ] and conversions
*
Fractions, random numbers, round result to the FIX settings
*
Polar and Rectangular Conversions
For
the polar and rectangular conversions, results are stored in the
following variables:
E:
x, r
F:
y, θ
Replay
The
last expression can be edited. To reedit the last expression,
simply press either the arrow keys [ ← ] or [ → ] and edit.
Characters can be inserted and deleted.
Statistics
There
are two primary statistics modes on the fx85WA:
*
SD (Single Deviation, 1variable statistics)
*
REG (Regression, 2variable statistics)
The
type of regressions are:
Lin:
Linear (y = a + b*x)
Log:
Logarithmic (y = a + b*ln x)
Exp:
Exponential (y = a + b*e^x)
Pwr:
Power (y = a*x^b)
Inv:
Inverse (y = a + b/x)
Quad:
Quadratic (y = a + b*x + c*x^2)
Data
points are entered with the [ M+ ] key with frequencies added with
the semicolon ( ; ). When data is entered, the x value is returned.
There is no data count indicator when [ M+ ] is pressed, I wish it
did. Keep this in mind.
All
the statistics registers are kept as shifted functions and alpha
registers, and they are:
SHIFT 1: mean x 
SHIFT 6: sy* 
RCL A: ∑x^2 
RCL F: ∑xy 
SHIFT 2: σx 
SHIFT 7: A (intercept) 
RCL B: ∑x 
RCL M: ∑x^3 
SHIFT 3: sx* 
SHIFT 8: B (slope, x coef.) 
RCL C: n 
RCL X: ∑x^2y 
SHIFT 4: mean y 
SHIFT 9: C (x^2 coef.) 
RCL D: ∑y^2 
RCL Y: ∑x^4 
SHIFT 5: σy 
SHIFT (: r (correlation) 
RCL E: ∑y 

*
labeled xσn1 and yσn1, respectively. (sample deviation)
Keyboard
The
fx85WA is a light calculator and pretty compact. The keys are
pretty solid, but also allow for fast typing. I like the labeling of
the keys, they are easy to read.
One
thing I am big fan of both STO (store) and RCL (recall) are primary
key functions. This is something we don’t see on scientific
calculators anymore, as often either STO or RCL is a shifted
function.
The
color of the font on the keys and labels are readable with good
contrast. The fx85WA is a pleasure to use.
Verdict
The
fx85WA serves a scientific calculator providing with lots of
functions. My only wish I had for this model is that top line’s
font is bigger, but that is addressed in later models.
This
model (and equivalent fx300W) is a challenge to find. I searched
ten pawn shops and several thrift shops for this model without
success.
Before
I go: I want to thank John Cadick for lending me his calculator to
review.
I
also want to give a table comparison of three Casio calculators:
(left to right) Casio fx85WA, Casio fx300MS, Casio fx300ES Plus 

Casio
fx85WA 
Casio
fx300MS 
Casio
fx300ES Plus 
Years
(approximate) 
About
19981999 
About
2000 Manual Date: 3/2011, 3/2013 
About
2004 Manual Date: 11/2011 
Number
of Keys 
50,
2 are the left and right arrow keys 
46
with keypad 
46
with keypad 
Number
of Digits 
10 
10 
10 
Contrast
the Screen? 
No 
Yes
(newer versions) 
Yes 
Modes 
[MODE]: COMP (Compute) SD (1Var Stats) REG (2Var Stats) Deg/Rad/Grad Fix/Sci/Norm 
[MODE]: Comp (Compute) SD (1Var Stats) REG (2Var Stats) Deg/Rad/Grad Fix/Sci/Norm Disp (ab/c, d/c, Dot, Comma) Contrast (newer versions) 
[MODE]: Comp (Compute) Stat (Statistics) Table (f(x), g(x)) [SETUP]: MathIO/LinearIO Deg/Rad/Grad Fix/Sci/Norm ab/c vs. d/c STAT (frequencies on) TABLE (f or f an g) Recurring Decimal Display (comma/decimal point) Contrast 
Statistics
Regressions 
Linear,
Logarithmic, Exponential, Power, Inverse, Quadratic 
Linear,
Logarithmic, Exponential, Power, Inverse, Quadratic 
Linear,
Quadratic, Logarithmic, Exponential, Power (both a*b^x and a*x^b),
Inverse 
Display 
2line
display, top: entry, bottom: result 
2line
display, top: entry, bottom: result 
Textbook
(can be set to 2line display) 
Exact
Answers 
Fractions 
Fractions 
Fractions,
Square Root, Pi 
Statistical
Registers 
Keyboard
and Registers: A: ∑x^2, B: ∑x C: n, D: ∑y^2 E: ∑y, F: ∑xy, M: ∑x^3, X: ∑x^2y Y: ∑x^4 
In
two menus: SSUM, SVAR 
In
a menu: STAT 
Statistical
Data Entry 
With
the [M+] button, use semicolon (;) to input frequency 
With
the [M+] button, use
semicolon (;) to input frequency 
In
a table, frequency
column can be turned on or off in the SETUP menu 
Multistatement
operations 
No 
Yes
(with [ : ] ) 
Yes
(with [ : ] ) 
Rect
to Polar Conversions 
E
= r, F = θ 
E
= r, F = θ 
X
= r, Y = θ Answer is displayed 
Polar
to Rect Conversions 
E
= x, F = y 
E
= x, F = y 
X
= x, Y = y Answer is displayed 
Extras 
N/A 
N/A 
GCD,
LMC, Int, Intg, RandInt, Factoring Integers (FACTOR) 
Power 
Solar/Batter
Backup: LR44 
Solar/Battery
Backup: LR44 
Solar/Battery
Backup: LR44 
Eddie
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Edward Shore. Unauthorized use and/or unauthorized distribution
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