## Monday, May 23, 2022

### Retro Review: Radio Shack EC-4026

Quick Facts:

Model:  EC-4026

Equivalent Of:  Casio fx-4500P, Casio fx-4500PA

Years:  1989-1991

Type:  Scientific, Programming

Batteries: 1 x CR-2025

Operating Mode:  Algebraic

Memory Registers: 26 (can be extended to 163 through the Defm command)

Program Steps:  1,103 (minimum of 7)

Number of Digits: 10 (display), 12 (precision)

Features

The Radio Shack EC-4026, a clone of the Casio fx-4500P, has a two line display.  On the top row shows formulas, equations, and prompts; and the bottom row displays results, and line numbers in programming mode.

The modes of the EC-4026 include:

*  Display Mode: Fix, Scientific Notation, Norm, Engineering Notation

*  Programming Write

*  BASE-N:  base conversions and Boolean Logic.  Binary numbers have 32 bits, signed.

*  Linear Regression:  y = A + Bx

*  Single Variable Regression (SD:  Standard Deviation mode)

Extended Memory

By default, there are 26 memory registers, A-Z.   You can use the square brackets [ ] to refer to memory registers indirectly, with the syntax  letter[# registers from letter].

A[ 0 ]: A

A[ 1 ]: B

A[ 2 ]: C

A[ 3 ]: D

...

Z[ 0 ]:  Z

To extend the number of memory registers, execute [ MODE ] [ Ans ] and enter the number of extended memory registers. For example, Defm 10 extends the number of registers to 36, allowing for registers Z[ 1 ] to Z[ 10 ].

Defm 0 returns he number of registers to the default 26.

Each extended memory costs 8 programming steps.

Independent Memory

The memory M is considered an independent memory with M+ and M- functions.

Formulas

In regular mode, we can store one formula (up to 127 steps) into memory with the IN command.

Expressions can be entered.  If the expression is entered in the form of var=formula, the result is stored into the variable.

The best part is that you can make prompts and result markers by adding a quoted comment next the variable.

Use the OUT command to recall the formula and CALC command to run the calculation.

Example:

[ CALC ]

AREA=     (243.2849351)

Integration

The integral command (∫) calculates the integrals of f(x) using Simpson's Rule.

∫( f(X), low, high, n)

n is an optional argument.  If n is included, the calculator uses 2^n partitions.  The maximum amount of partitions is 2^9 (512).   During calculation, the screen goes blank except for mode indicators.

Programming

The programming module is an early version of Casio basic.   Each program can have a file name.  The file names are sorted by chronologically.  In write mode, each line has a file number and a line number. (F# L#).

Store calculations by using the syntax:

var=expressions

Variables can be either be defined (with their values) or undefined (the program will ask for the values each time a loop returns).   Define all the variables with the Fixm command.   We can undefine variables with the curly brackets { }.

The If structure is a little different, with the following symbols are used:

⇒  Then

≠⇒ Else  ( [ 2ndF ] [ a b/c ] )

◺ EndIf

(condition) ⇒ (do if true) : or ⊿ ≠⇒ (do if false) : or ⊿ ◺ (the if loop ends)

Subroutines, Pause (up to 4.5 seconds, with terms of half-seconds), and Goto/Labels (0-9, specific to each program) are included.

The manual will also list a way to designate a program file as a data bank of names and their telephone numbers.

Sample programs follow.

Volume of a Frustum of a Cone:

Name:  FRUSTUM.CONE

F# L1  {H,Q,R}      // undefine H, Q, R

F# L2  H"HEIGHT"   // prompt for H with the prompt "HEIGHT?"

F# L3  Q"SMALL R" // prompt for Q with the prompt "SMALL R?"

F# L4  R"BIG R"  // prompt for R with the prompt "BIG R?"

F# L5  V"VOL"=H×(Q²+R²+Q×R)×π/3    // calculate volume, display V with "VOL="

Function Table

Name: TABLE

F# L1  {A,B,C}   // undefine A,B,C

F# L2  A"BEG"  // prompt for A with the prompt "BEG?"

F# L3  B"END" // prompt for B with the prompt "END?"

F# L4  N"POINTS" // prompt for N with the prompt "POINTS?"

F# L5  H=(B-A)/N

F# L6  X=A

F# L7  Lbl 0   // start the table

F# L8  X⊿   // display X

F# L9  F=2X-1⊿  // insert f(x) here (F=f(x))

F# L10  X=X+H

F# L11  X≤B⇒Goto 0:◺"FIN"  // if-then structure

Closing Thoughts

The EC-4026 is a great programming calculator.  The programming structure does present a learning curve due it being a beginning version of Casio basic.

Sources

"Radio Shack EC-4026"  MyCalcDB.  April 21, 2014.   Last Accessed April 3, 2022.  http://mycalcdb.free.fr/main.php?l=0&id=4059

Toth, Viktor T.  "Casio fx-4500P"  rskey.org   2022.   Last Accessed April 3, 2022.  https://www.rskey.org/fx4500p

Toth, Viktor T. "Radio Shack EC-4026" rskey.org.  2022.  Last Accessed April 3, 2022.  https://www.rskey.org/ec4026

Until next time,

Eddie

All original content copyright, © 2011-2022.  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.

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