Review: EAI-350 Scientific Calculator

Review:  EAI-350 Scientific Calculator 

Basic Facts

Type:  Scientific
Display:  Two Line:  entry on the top and result on the bottom
Power:  Solar with battery backup, LR44
Memory Registers: 8:  A,B,C,D,E,F,X,Y,M
Price: $8.67, sold online:  https://www.eaieducation.com/Product/560440/CalcPal%C2%AE_EAI-350_Scientific_Calculator.aspx
Documentation:  2 fold out manuals, one full manual and one short manual detailing the more advanced functions

Keypad

The EAI-350 scientific calculator is similar to the Casio fx-991MS and fx-115MS.  The differences:

The keys are blue, white, and lime green.  The case is dark silver.  The keys work fine, but I don't think they are as solid as the Casio calculators.  The biggest flaw came in the keypad, I had to press the up on the keypad several times and with a firm touch.  This is not a deal breaker, just be something to aware of. 

Modes

The EAI-350 has a rich set of features.    The modes include:

*  Compute mode (general math mode)
*  Complex Mode  (arithmetic, x^2, √, Abs, arg, rectangular/polar conversions)
*  Statistics (single variable, Linear Regression, Logarithmic Regression, Exponential Regression, Power Regression, Inverse Regression, Quadratic Regression)
*  Base Operations (Decimal, Hexadecimal, Octal, Binary)
*  Equation Mode (2 x 2 and 3 x 3 linear systems, quadratic equations, cubic equations)
*  Matrices (3 matrices, up to 3 x 3)
*  Vectors (3 vectors, up to 3 elements)

One thing that I noted is that the logic functions only include AND, OR, and XOR.  Entering negative integers will require the use of the minus ([ - ]) key. 

Fractions

Fractions can be entered and calculated.  Results are simplified.  Fractions can be displayed as mixed fractions or improper fractions. 

Calculus

Calculus functions of the EAI-350 include the numeric integral, numeric derivative, evaluation, and a solve function.  The solve function can solve for any variable. 

Engineering Symbols

You can attach engineering symbols (powers of 10) to numbers from f (10^-15) to T (10^12). 

Constants and Conversions

The EAI-350 has 40 sets of conversions and 40 scientific constants.  You will need the fold out manual because calling the conversion and constants by numerical code.  The manual states that the constants are based on the 1992 ISO Standard and 1998  CODATA recommended values.  (a little dated)

Verdict

The EAI-350 is a good alternative to the Casio calculators.  The keyboard could be more solid, but it works.  I wish I could adjust the screen contrast, so be aware of where the calculator is operated because the screen can reflect. 

Eddie

All original content copyright, © 2011-2019.  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.

Optics: Transmitted Angle, Critical Angle

Optics:  Transmitted Angle, Critical Angle

Formulas Used

Reflected Angle:  θr = θ

Transmitted Angel:  θt = asin((n1 * sin θ)/n2)

Critical Angle:  θc = asin(n1/n2),  n2 > n1

Perpendicular Frensel Parameters (t, r):

t = (2 * n1 * cos θ) / (n1 * cos θ + n2 * cos θt)

r = (n1 * cos θ – n2 * cos θt) / (n1 * cos θ + n2 * cos θt)

Parallel Fresnel Parameters (t, r):

t = (2 * n1 * cos θ) / (n1 * cos θt + n2 * cos θ)

r = (n1 * cos θt – n2 * cos θ) / (n1 * cos θt + n2 * cos θ)

Table of Indices of Reflection (n)

Air	1.00	Moissanite (SiC)	2.65
Carbon Dioxide (CO2)	1.0045	Pyrex	1.47
Cubic Zirconia	2.15	Salt (NaCl)	1.54
Diamond	2.42	Sapphire	1.76
Glass	1.52	Silicon	3.45
Ice	1.31	Water	1.33

HP Prime Program FLATOPTIC

EXPORT FLATOPTIC()

BEGIN

// 2017-12-17 EWS

// Solar Energy

// Change to degree

HAngle:=1;

// index of refraction

LOCAL L0:={1,1.0045,2.15,2.42,

1.52,1.31,2.65,1.47,

1.54,1.76,3.45,1.33};

LOCAL L1:={"Air","CO2",

"Cubic Zirconia","Diamond",

"Glass","Ice",

"Moissanite (SiC)","Pyrex",

"Salt (NaCl)","Sapphire",

"Silicon","Water"};

LOCAL L2:={"Perpendicular",

"Parallel",

"None"};

LOCAL n1,n2,k1,k2,θ,t,r;

LOCAL θc,θt,θr,x;

INPUT({{k1,L1},{k2,L1},θ,{x,L2}},

"Optic - Flat Interface",

{"Medium 1: ","Medium 2: ",

"Angle (°): ","Polarized?"}

);

// Calculation

PRINT();

θr:=θ;

PRINT("Reflect Angle: "+θr+"°");

n1:=L0(k1); n2:=L0(k2);

IF n2>n1 THEN

θc:=ASIN(n1/n2);

PRINT("Critical Angle: "+θc+"°");

END;

θt:=ASIN(n1*SIN(θ)/n2);

PRINT("Transmitted Angle: "+

θt+"°");

IF x==1 THEN

t:=(2*n1*COS(θ))/

(n1*COS(θ)+n2*COS(θt));

r:=(n1*COS(θ)-n2*COS(θt))/

(n1*COS(θ)+n2*COS(θt));

PRINT("t: "+t);

PRINT("r: "+r);

END;

IF x==2 THEN

t:=(2*n1*COS(θ))/

(n1*COS(θt)+n2*COS(θ));

r:=(n1*COS(θt)-n2*COS(θ))/

(n1*COS(θt)+n2*COS(θ));

PRINT("t: "+t);

PRINT("r: "+r);

END;

END;

TI-84 Plus CE Program

"EWS 2017-12-17"

{1,1.0045,2.15,2.42,1.52,1.31,2.65,1.47,1.54,1.76,3.45,1.33}→L6

Degree

For(K,1,2)

Disp "1. AIR 2. CO2 3. CUB.ZIC.","4. DIAMOND 5. GLASS 6. ICE","7. MOISANITE","8. PYREX 9. NACL","10. SAPPHIRE 11. SIL.","12. WATER"

Input M

If K=1:M→N

End

L6(N)→N:L6(M)→M

Input "INCIDENT: °",θ

sin^-1(N*sin(θ)/M)→A

Disp "TRANSMITED: °",A

If M>N:Then

sin^-1(N/M)→C

Disp "CRITICAL: °",C

End

Pause

Menu("POLARISE?","PERPENDICULAR",1,"PARALLEL",2,"NONE",3)

Lbl 1

(2Ncos(θ))/(Ncos(θ)+Mcos(A))→T

(Ncos(θ)-Mcos(T))/(Ncos(θ)+Mcos(T))→R

Disp "T",T,"R",R

Goto 3

Lbl 2

(2Ncos(θ))/(Ncos(T)+Mcos(θ))→T

(Ncos(T)-Mcos(θ))/(Ncos(T)+Mcos(θ))→R

Disp "T",T,"R",R

Lbl 3

Source:

Klaus Jäger, Olindo Isabella, Arno H.M. Smets, René A.C.M.M. van Swaaij, Miro Zeeman  Solar Energy: Fundamental, Technology, and Systems  Delft University of Technology, 2014

(no money is made from this blog entry)

Hopefully you find this useful.

Eddie

This blog is property of Edward Shore, 2017

Review: Casio fx-260 Solar II (fx-82 Solar II)

Review:  Casio fx-260 Solar II (fx-82 Solar II)

 Company:  Casio

Year:  2017

Type:  Scientific

Power:  Solar

Statistics: 1 Variable

Operating System:  AOS (classic)

Cost:  $8.99

So New?

Ironically, I was not able to find the fx-260 Solar II online, but saw it on a very rare trip to WalMart.  The Casio fx-260 Solar II calculator is so new that still isn’t featured on the Casio’s website (as of 3/27/2017). 

As a note:  The fx-260 is the name for the version sold in the United States.  Internationally, the calculator is known as the fx-82 Solar II, and Casio does have that calculator on its website:

https://www.casio-europe.com/euro/products/school-and-graphic-calculators/technical-scientific-calculator/fx-82solar2/

An Update of a Classic

 

fx-260 Solar original on the left, fx-260 Solar II on the right  (named fx-82 Solar (II) internationally)

The fx-260 Solar II is an update of the very classic (and still selling) Casio fx-260 Solar (outside the United States, it’s the fx-82 Solar).  Functionally, the fx-260 Solar II is the same as the classic fx-260.  As a reminder:

* Trigonometric functions

* Angle conversions: polar, rectangular, to degrees (Shift Mode 4), to radians (Shift Mode 5), and to grads (Shift Mode 6)

* Random numbers

* Logarithms and exponents

* 1 Variable Statistics

* Fractions (up to a maximum of 10 digits between the whole, numerator, and denominator parts)

* DMS/Decimal math and conversions

Pretty handy for a basic scientific calculator.  The fx-260 Solar II, like its predecessor runs entirely on solar and light power, hence a completely green calculator.  50 lux is required.

There is a NF version which was stated on the quick manual that came with the fx-260 Solar II.  The NF stands for “no fraction” and the diagram shows the fraction button [ a b/c ] button disabled.

The percent key still works the same as the predecessor.  The keystrokes:

Find N% of W:   W [ * ] N [Shift] [ = ] (%)

W is N% of the whole:   W [ ÷ ] N [Shift] [ = ] (%)

Markup/Tax:   W [ * ] N [Shift] [ = ] (%) [ + ]

Discount:  W [ * ] N [Shift] [ = ] (%) [ - ]

The differences between the fx-260 Solar II are:

 

The back of the fx-260 Solar II

1.  The processor is faster, most noticeable when try to calculator n! when  50 < n < 69.  In reality, it can be seen as negligible since the predecessor is no slow poke. 

2.  The fx-260 Solar II is has a more compact design than the original fx-260 Solar.  The fx-260 Solar II is close to a size of an iPod Touch/iPhone.  Per the manual, the dimensions of the fx-260 Solar II are 3/8” height, 2 3/4” width, and 4 3/4” depth. 

3.  The one difference I’m not a fan of is how the mode reminders are moved to the back of the calculator.  Furthermore, the reminders are white text on a white background.  It is only because of the etching that the reminders could be readable. 

Easter egg: I think this is the first time Casio dated their manual (2017). 

Final Verdict

If you are fan of small calculators, solar calculators, Casio, basic level scientific calculators, or just want something nice to add to your collection, then the fx-260 Solar II (and the original fx-260 Solar) is a nice pick up for not much money.

Eddie

This blog is property of Edward Shore, 2017.

Retro Review: Casio CM-100 Computer Math Calculator

Retro Review:  Casio CM-100 Computer Math Calculator

Company:  Casio

Model:  CM-100

Type:  Computer Math, Boolean Algebra

Year: 1986

Power: Solar

Memory Registers: 1

Being Green

The CM-100 is fully ran by solar power, so make sure you have adequate light to operate the CM-100. 

Base Calculations

The CM-100 is part of a rare genre of scientific calculator: the calculator that is dedicated to base conversions, bit shifting and rotating, and displaying integers up to 32 bits (dwords).  Perhaps the most famous calculator of this family is the much sought after Hewlett Packard HP-16C.  On the Texas Instruments side, there was the TI-Programmer.

There are five modes on the CM-100:

COMP:  Math Mode.  All numbers are represented in decimal with floating point arithmetic.  The parenthesis, %, √, x^2, 1/x, HMS conversions, and memory functions are the primary functions on the 2^nd and 3^rd row of keys.  Pressing [ ON ] clears the calculator and sets the CM-100 to COMP mode.

Entering numbers in degrees-minutes-seconds requires a repeated press of [ hms ].

Note: For the BIN, OCT, DEC, HEX modes, the parenthesis and memory functions become shifted functions, and instead of the %, √, x^2, 1/x, DMS conversions, we have BLK (block scrolling), shifting, NOT, AND, OR, XOR, and rotation. 

BIN:  Binary Mode.  All integers are represented in base 2.   Pressing [BIN] converts the integer to binary.

OCT: Octary Mode.  All integers are represented in base 8.  Pressing [OCT] converts the integer to octave.

DEC:  Decimal Mode.  All integers are presented in base 10.  Pressing [DEC] converts the integer to decimal.

HEX:  Hexadecimal Mode.  All integers are presented in base 16.  Pressing [HEX] converts the integer to hexadecimal.  The keys A-F become available.  As a reminder:

A = 10

B = 11

C = 12

D = 13

E = 14

F = 15

Seeing Blocks

The CM-100 allows the user to set the bit sizes from 1, 4, 8, 10, 16, and 32.  Since the calculator can only fit so many digits on the screen, up to 10, the [BLK] key is to available for the user to cycle through the blocks:

Block 4 | Block 3 | Block 2 | Block 1

Example:  Display 3,723,601 in binary bits.  Assuming base 32 is set (which I think is the default).  Press [BLK] to cycle through the blocks.  The decimal points indicate which block you are viewing.

Block 1  (3 decimal points to the left)	.1.0.01001
Block 2   (2 left, 1 right)	.1.1010001.
Block 3   (1 left, 2 right)	.0011100.0.
Block 4   (3 right)	000000.0.0.

Hence, 3,723,601 in binary is 00000000 00111000 11010001 1001001.

To Sign or Not To Sign

The CM-100 has two modes when comes to signs:

Unsigned (no display indicator):  All integers are 0 or positive.  The range is from 0 to (2^n) -1, where n is the number of bits. 

Signed (a SIGN indicator):  Integers can be positive or negative.  The first bit is the sign bit which dictates the sign of the integer (easiest to understand in Binary mode).  The range is from -2^(n-1) to 2^(n-1) – 1. 

Example:  In Binary, 4 Bits: 

Binary	Unsigned Mode Representation	Signed Mode Representation
1000	8	-8
1111	15	-1

Shifting Integers

It is well known that most calculators that have base calculations include the Boolean algebra functions NOT, AND, OR, and XOR; pretty standard.  What the CM-100 adds is the shift and rotate functions. I am going to try to explain the shifts as far I understand them – if you have a better explanation, please comment and it will be appreciated.  I think this is best understood in the context of Binary.

A-Shift:  Arithmetic Shift Left/Right.  This moves the bits left or right by 1.  Any bit that “shoved” off is discarded.  In Signed mode, Arithmetic Shift Right replaces the sign bit with whatever was the previous signed bit.  Otherwise, the new bit is 0.

Shift:  Logical Shift Left/Right.  This moves the bits left or right by 1.  Any bit that “shoved” off is discarded.  The replaced bit is always 0.

Rotate:  The bits rotates left or right by one digit.  All bits are otherwise retained.

Arithmetic Shift vs. Logical Shift

The only difference is when you are working with signed integers and when the shifts are to the right.

To illustrate, I executed both shifts on the CM-100, in Signed and Binary modes with 4 bit size set.  Arithmetic Shift Right ([ S ] [OCT] (A S>)),  Logical Shift Right ([ S ] [AND] (Shift>)).

Starting Integer:  0101

Arithmetic Shift Right	0010	(Logical) Shift Right	0010
Arithmetic Shift Right	0001	(Logical) Shift Right	0001
Arithmetic Shift Right	0000	(Logical) Shift Right	0000

Starting Integer:  1001

Arithmetic Shift Right	1100	(Logical) Shift Right	0100
Arithmetic Shift Right	1110	(Logical) Shift Right	0010
Arithmetic Shift Right	1111	(Logical) Shift Right	0001

Vs. the HP-16C

New Price of a CM-100:  $20(?)

New Price of an HP-16C:  $150

Obviously, the HP-16C was also programmable (203 bytes) and operated in RPN mode.  Furthermore, the HP-16C had double arithmetic (multiplication, division, and remainder).  However, the CM-100 has the decimal/decimal-degrees-seconds conversion and it was solar.

If you want to have a base-dedicated calculator and you had the budget in mind, consider buying the CM-100.  I bought one through eBay (Wolfs Big Bad Garage) for about $25.  The HP-16C would cost at least $100. 

Verdict

I recommend this model.  It is convenient way to convert between bases, work with common bit sizes, and execute computer algebra on the CM-100.  It’s well worth the price.

Source:  http://www.calcuseum.com/poc_13622.html

If you want to take a look at the manual, check out this link (scroll to the bottom):  http://casio.ledudu.com/pockets.asp?type=1300&lg=eng

Eddie

This blog is property of Edward Shore, 2017