Casio fx-50F/Radio Shack EC-4024 Program Collection: October 2026

Casio fx-50F/Radio Shack EC-4024 Program Collection: October 2026

Notes:

* The fx-50F/EC-4024 has a 29 step program space between two program spaces. Program steps can not be edited but can be cleared by [SHIFT] [ C ] (PCL) key sequence.

* Formula calls can not be included as a program step, but scientific constants can be. The values for the constants most likely are from the Japan Standards of 1978 (JISZ-8020-1978), so a little dated to 2026 standards.

* The Casio fx-10F is similar as fx-50F/EC-4024 except that the fx-10F does not have the scientific constants and has a slightly inclined keyboard.

* Mode changes can be included. SHIFT and Kin arithmetic calls are merged.

The programs presented today require inputs to be stored in registers 1-6 using [ SHIFT ] [ Kout ] (Kin) ((K)onstants In).

Angle Between 2 Lines (in Degrees)

Θ = arctan( abs((y – x) ÷ (1 + x * y)) )

abs(x) = √(x^2), key sequence: [ x² ] [ √ ]

x: slope of line 1 (Kin 1)

y: slope of line 2 (Kin 2)

Program Code (20 steps):

MODE 4 (degree)

(

(

Kout 2

-

Kout 1

)

÷

(

1

+

Kout 1

×

Kout 2

)

)

x²

√

TAN^-1

=

Maximum and Minimum of Two Numbers

The two numbers are stored in registers 1 and 2 (Kin 1, Kin 2).

max(x,y) = (x + y + abs(x – y)) ÷ 2 = min(x,y) + abs(x – y)

min(x,y) = (x + y - abs(x – y)) ÷ 2 = max(x,y) - abs(x – y)

Program Code (21 steps):

Kout 2

-

Kout 1

=

x²

√

Kin 3

(

Kout 1

+

Kout 2

+

Kout 3

)

÷

2

=

HLT (show maximum)

-

Kout 3

= (show minimum)

Terminal Velocity of a Spherical Object

vt = √(2 * g * mass ÷ (ρ * cd * exposed area of the object) (units: m/s)

≈ √(34.05656 * mass ÷ (π * radius^2))

The following constants are assumed:

g = 9.80665 m/s² (Earth’s gravitational constant)

ρ ≈ 1.225 kg/m³ (air pressure)

cd = 0.47 (coefficient drag of a sphere)

2 * g ÷ (ρ * cd) ≈ 34.06565 m^4/(s^2 kg)

Program Code (19 steps):

Kout 1

×

3

4

.

0

6

5

6

5

÷

(

π

×

Kout 2

x²

)

=

√

=

Ideal Thermal Voltage and Shockley Diode Equation

Thermal Voltage:

vt = k * T ÷ q * 10^3 (mV)

Shockley Diode Equation:

Id = Is * (exp(vD ÷ (n * vt)) – 1)

Ideal: n = 1

Inputs:

Is: scale current in milliamps (mA) Kin 1

Vd: diode voltage in millivolts (vA) Kin 2

T: temperature in degrees Kelvin (K) Kin 3

Outputs:

vt: Thermal Voltage (mA),

Id: diode current (mV)

Constant used (see comments on the scientific constants above):

k: Boltzmann Constant ([SHIFT] [ 8 ]): 1.380662 * 10^-23 J/K

(q) e: Electron Charge ([SHIFT] [ 4 ]): 1.6021892 * 10^-19 C

Program Code (21 steps):

Kout 3

×

k (SHIFT 8)

÷

e (SHIFT 4)

×

3

10^x

=

HLT (see vt: thermal voltage)

1/x

×

Kout 2

=

e^x

-

1

=

×

Kout 1

=

Source:

“Shockley Diode Equation” Wikipedia. Last Edited November 13, 2025.

https://en.wikipedia.org/wiki/Shockley_diode_equation

Retrieved June 19, 2026.

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.

HP 67 Programs… Almost 50 Years Later

 HP 67 Programs… Almost 50 Years Later

Both downloads are in PDF format. This is for use for the HP 67 and its emulators, or really almost any RPN scientific calculator. Enjoy!

Volume 1:

https://drive.google.com/file/d/114H4D0hcOjxDj_MHQNvwDBUJV3chlpdC/view?usp=sharing

Countdown of HP 67 "seconds"

Random Numbers

Snell's Law

Circle: Area and Circumference

Sphere: Surface Area and Volume

Angle Between 2 Lines with Slopes x and y

Sum of Powers

Adding Complex Numbers

Multiplying Complex Numbers

Complex Number to a Real Power

Permutation

Combination (with duplicating X and Y stack values)

Speed of Sound Approximation (in meters per second)

Finance: Present Value Annuity Factor (including setting N and I% with monthly payments)

Distance Between Two Points (x,y) and (z,t)

Horizontal Curve

Volume 2:

https://drive.google.com/file/d/1RPK2C879JeiyReox1SOTeAOQc_7QYdUN/view?usp=sharing

Sigmoid Function

Logit Function

Solving Linear Equations

Solving Monic Quadratic Polynomials (real roots only)

Intensity of a Spherical Light Source

Determinant of a 2 x 2 Matrix

Air Density of Dry Air

Time Dilation Factor

Simple Interest

Calculus: Area Under the Curve of a Linear Function

Horizontal Curve Solution given Radius and Central Angle

Freezing Altitude Levels: Dry and Wet

HP 67 Solvers:

Temperature Conversions

Cost-Sell-Margin

Decibel Gain/Loss

Eddie

All original content copyright, © 2011-2025. 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.

Casio fx-4000P - The Programs I took on Vacation

 Casio fx-4000P - The Programs I took on Vacation

I was on vacation in Atascadero last May 2024 at a car conference with my partner. I may not have classic cars, but I do have classic calculators. Here the programs I took with me in Casio fx-4000P.
I also took my HP 45 with me as well.

Total: 448 bytes out of 550 bytes ( ^ => x^y)

Prog 0: Quadratic Equation: Po Shen way: x^2 + B * x + C = 0, built for real roots (39 steps)

“ B “ : ? → B : “C” : ? → C : B² ÷ 4 – C → W ◢ -B ÷ 2 - √W ◢ Ans + 2 × √W

Prog 1: Law of Cosines - Side Z (45 steps)

Deg : “X” : ? → X : “Y” : ? → Y : “C” : ? → C : X² + Y² – 2 × X × Y × cos C : √Ans → Z

Prog 2: Law of Cosines - Angle C (49 steps)

Deg : “X” : ? → X : “Y” : ? → Y : “Z” : ? → Z : ( X² + Y² – Z² ) ÷ ( 2 × X × Y ) : cos^-1 Ans → C

Prog 3: Area of Triangle – Heron’s Formula (55 steps)

“X” : ?→X : “Y” : ?→Y : “Z” : ?→Z : (X + Y + Z) ÷ 2→S : √( S×(S – X)×(S – Y)×(S – Z))

Prog 4: Speed of Sound in Dry Air (53 steps)

All constants, γ, R, M are taken care of in the formula, T = temp in °F

Conversions: 1 m/s = 2.236936 mph, 20.04503702 * 2.236936 = 44.83946493

“ T “ : ?→T : 5÷9 × (T – 32) + 273.15 : 20.04503702 * √Ans : 2.236936 * Ans → S

Prog 5: Horizontal Curve Analysis Given Central Angle and Radius (52 steps)

I = central angle, R = radius, L = arc length, C = chord length

Deg : “I” : ?→I : “R” : ?→R : “L=” ◢ π×R×I ÷ 180 → L ◢ “C=” ◢ 2×R× sin(I ÷ 2) → C

Prog 6: D = Displacement of a Cylinder (in) (36 steps)

B = bore (in), S = stroke (in), N = number of cylinders

“B” : ? → B : “S” : ? → S : “N” : ? → N : π × B² × S × N ÷ 4 → D

Prog 7: Tire Size (in) (36 steps)

S = section width (mm), A = aspect ratio, R = rim diameter (S, A, R → )

“S” : ? → S : “A” : ? → A : “R” : ? → R : S × A ÷ 1270 + R → T

Prog 8: Air Pressure for height up to 36,089 ft above sea level (inHg) (45 steps)

This is with constants already completed (g, M, R, etc.)

“H” : ?→H : 29.92126 × (1 - 6.875 × 10^-6 × H) x^y 5.255876329 → P

Prog 9: Breaking Distance in Feet Given the Car’s Velocity in Miles Per Hour (35 steps)

“V” : ? → V : V × 22 ÷ 15 : Ans × 1.5 + Ans² ÷ 45.04367 → D

Source:

“Breaking Distance” Wikipedia. Last Edited March 30, 2024. Accessed April 29, 2024.

https://en.wikipedia.org/wiki/Braking_distance

Hagberg Media AB. “Stopping distance = reca2tion distance + breaking distance” 2024.

Accessed April 29, 2024. https://korkortonline.se/en/theory/reaction-braking-stopping/

Just for fun,

Eddie

All original content copyright, © 2011-2024. 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.

HP 32S II Statistical Formulas

HP 32S II Statistical Formulas

Statistics Formulas

The 32S II can store formulas for evaluations, including formulas involving stat variables.  

Covariance:

C = r × sx × sy

Root Mean Square Based on X Variable Statistics:

R = SQRT( Σx^2 ÷ n )

Z-Score Based on X Variable Statistics:  

Z = (X - x-bar) ÷ sx

Accessing Stat variables:

r:  [ right shift ]  [ LN ] (L.R.) [ y^x ] (r)

sx:  [ right shift ] [ 1/x ] (s, σ), [ √x ] (sx)

sy:  [ right shift ] [ 1/x ] (s, σ), [ LN ] (sy)

Σx^2:  [ right shift ] [ Σ+ ] (SUMS) [ e^x ] (x)

n:  [ right shift ] [ Σ+ ] (SUMS) [ √x ] (n)

x-bar:  [ right shift ] [ y^x ] (x-bar,y-bar) [ √x ] (x-bar)

Example

Data:  (x, y)

(10.4, 20)

(13.5, 18)

(16.8, 15)

(19.1, 13.9)

Enter statistical data:  y [ENTER] x [ Σ+ ]

Some stats:

x-bar = 14.95

y-bar = 16.725

r = -9.9503133E-1

Covariance:  Solve for C

C = -10.555

Result is stored in C

Root Mean Square:  Solve for R

R = 15.3089842903

Result is stored in R

Z-Score Based on X Variable Statistics:   Solve for Z

X?  15,  Z = 1.31382E-2

X?  17,  Z = 5.38666E-1

Result is stored in Z

Formulas vs. Programs

If we are going to evaluate formulas (that is, solve for the variable left of the equals sign), we could also enter and use programs.   The programs for the above three formulas:

Covariance:

C01  LBL C

C02  r

C03  sx

C04  ×

C05  sy

C06  ×

C07  RTN

Root Mean Square:

R01  LBL R

R02  Σx^2

R03  n

R04  ÷

R05  SQRT

R06  RTN

Z Score:  (x is in the X stack)

Z01  LBL Z

Z02  x-bar

Z03  -

Z04  sx

Z05  ÷

Z06  RTN

Byte Consumption Comparison

Covariance

Formula:  12 bytes

Program:  10.5 bytes

Root Mean Square

Formula:  12 bytes

Program:  9 bytes

Z Score

Formula: 15 bytes

Program:  9 bytes

From sample set, programs are shorter than formulas.  Is this true in general?

Eddie

All original content copyright, © 2011-2023.  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. 

Fun with the TI-80

Fun with the TI-80

TI-80 Program D2DMS - Decimal to Degrees-Minutes-Seconds

Variables:

Decimal Format:

D = decimal

DMS Format:

H = degrees/hours, M = minute, S = seconds

INPUT “DEC:”,D

IPART D→H

IPART (60*FPART D)→M

60 * FPART (60 * FPART D)→S

DISP “H,M,S:”,H,M,S

TI-80 Program DMS2D - Degrees-Minutes-Seconds to Decimal

Variables:

Decimal Format:

D = decimal

DMS Format:

H = degrees/hours, M = minute, S = seconds

INPUT “H:”,H

INPUT “M:”,M

INPUT “S:”,S

H + M/60 + S/3600 → D

DISP “DEC:”,D

TI-80 Program QUADRAT - Quadratic Equation

Variables:

A, B, C are coefficients of the equation Ax^2 + Bx + C, where the discriminant D:

D = B^2 – 4*A*C

If D≥0, then the roots are real and stored in X and Y.

If D<0, then the roots are complex and are in the form of conjugates X ± Yi.  X is the real part, Y is the imaginary part.

DISP “AX^2+BX+C=0”

INPUT “A:”,A

INPUT “B:”,B

INPUT “C:”,C

B^2 – 4AC → D

DISP D 

-B / (2A) → E

IF D≥0

THEN

E + √D/(2A) → X

E - √D/(2A) → Y

DISP “R1:”,X

DIPS “R2:”,Y

ELSE

E → X

√-D / (2A) → Y

DISP “RE:”,X

DISP “IM :”,Y

END

Annuity Factors

Variables:

I = periodic interest rate

N = number of payments/periods/deposits

TI-80 Program USFV – Annuity Future Value Factor

INPUT “I:”,I

INPUT “N:”,N

( (1+.01)^N – 1)/(.01I) → F

DISP F

TI-80 Program USPV – Annuity Present Value Factor

INPUT “I:”,I

INPUT “N:”,N

(1 – (1 + .01I)^-N)/(.01I) → P

DISP P

Two Dimensional Vector Operations

Let two vectors be defined as V1 = [A, B] an V2 = [C, D].  The program calculates the dot product, stored in E, norm of V1, stored in F, norm of V2, stored in G, and the angle between V1 and V2 in degrees, stored in H.

TI-80 Program VECTOR2

DEGREE

DISP “V1:”
INPUT A

INPUT B

DISP “V2:”

INPUT C

INPUT D

AC + BD → E

√(A^2 + B^2) → F

√(C^2 + D^2) → G

COS^-1 (E /(F*G)) → H

DISP “NORM V1:”, F

DISP “NORM V2:”, G

PAUSE

DISP “DOT:”, E

DISP “ANGLE:”, H

Simplistic Logistic Regression

Fit data (x,y) to the equation:

Y = 1 / (A + B*e^(-X))

Refer to http://edspi31415.blogspot.com/2017/04/hp-prime-and-ti-84-plus-ce-simple.html

TI-80 Program SIMPLOG

INPUT “L1:”, L1

INPUT “L2:”, L2

e^-L1 → L1

1/L2 → L2

LINREG(aX+b) L1, L2

a→A: b→B

DISP “1/(B+Ae^X)”,A,B

PAUSE

DISP “CORR^2”,r^2

Eddie

This blog is property of Edward Shore, 2017