Monday, January 16, 2017

Retro Review: Radio Shack EC-4036

Retro Review:  Radio Shack EC-4036

Radio Shack EC-4036

Radio Shack EC-4036

Company:  Radio Shack
Years:  most likely late 1980s to early 1990s
Type:  Scientific, Programming
Number of Steps: 40
Operating System: AOS (post-script)
Memory Registers: 3 (M, A, B)

Chipset:  Sharp LI3301A

Sharing the Same Chipset

According to a YouTube video from badogember csatornája, the EC-4036’s chip set is Sharp LI3301A which is shared with many other calculators such as the Citizen SRP-145, Citizen SRP-40, and Aurora TB607.  This means that this calculator line up and functions are cloned and marketed by many companies.  (Link to that video: ).  The Logtech LC-604 is also part of this chip subset. 

I am thankfully that the EC-4036 is cloned (or is a clone) because I couldn’t find a manual for Radio Shack online (not even their website has a manual for this particular calculator).  Since the Citizen SRP-145N has the same chipset, its manual will have to do.  (Link: )

There is also a discussion on the Museum of HP Calculators about the Citizen SRP-145 here: 

A member of the Minimalist Club

The EC-4036 has 40 programming steps.  Furthermore, only simple programming is allowed, as there are no loops, alphabetic characters, or tests.  Unfortunately, the programming is “blind” with no way to step backwards and forwards.  Programming the EC-4036 will require either trust or writing the program down first (I always do the latter).

The good news is that you can be Statistics mode when entering programs and take advantage of the one-variable statistics functions (mean, standard and population deviation, sums Σx and

There are two functions dedicated to the programming mode:

HALT:    Pauses the calculator and shows the result. This is very handy.  To continue execution, press [COMP].

[ x ]:  I originally though that this is a integer part function.  It is not, this is the Input function.  When an [ x ] is encountered, the calculator asks for a numeric input.  Press [COMP] to continue.

The EC-4036’s program is erased each time you start a new program, but with 40 steps, I image that all the programs for the EC-4036 will be short and will be easy to input when required.

When programming, program like you are actually making a calculation.  This really comes into play when you want insert a prompt step ([x]).  After pressing [x], enter a valid number to continue the calculation.  Planning is definitely a key.


The keys are rubbery and soft to the touch.  Thankfully, the keys are still responsive.

I wish the labeling on some to the keys could be clearer. Here are the mapping of the most confusing looking keys:

[A >A] (CD CAD):
Primary Function:  Recall A.  If a number is entered first, it multiplies it by A. 
Second Function:  Store the number in the display to register A.
Primary Function Stat Mode: Clears the last data point entered
Second Function Stat Mode: Clears all data points

[B >B] (n Σx)
Primary Function:  Recall B.  If a number is entered first, it multiplies it by B. 
Second Function:  Store the number in the display to register B.
Primary Function Stat Mode: Recall n (number of data points)
Second Function Stat Mode: Recall Σx (sum of all data points)

[ MS ] (x-bar Σx^2)  
Primary Function:  Stores the number in register M 
Second Function:  N/A
Primary Function Stat Mode: Recall the arithmetic mean of all data points
Second Function Stat Mode: Recall Σx^2 (sum of all squared data points)

[ MR ] (s σ)
Primary Function:  Recalls the number in register M 
Second Function:  N/A
Primary Function Stat Mode: Recall sample deviation (sx)
Second Function Stat Mode: Recall population deviation (σx)

[ M+ ] (DATA)
Primary Function:  Adds the number in the display to register M 
Second Function:  N/A
Primary Function Stat Mode: Enters the number as a data point
Second Function Stat Mode: N/A

Your Basic Scientific Calculator

The EC-4036 has the basic scientific functions: trigonometric, logarithmic, exponential, hyperbolic, power, factorial, and decimal/degrees-minutes-seconds conversion.

When the [2ndF] and HYP is evoked, the 2F and HYP indicators take the display.  For some reason I like this. 

Final Verdict

A nice collector calculator to have.  I wouldn’t pay a large amount of money for it however, I paid about $6.  If you like a small programming calculator or a challenge, this is one to consider.

Now for a few sample programs.

EC 4036 Program:  Percent Change

[COMP] new [COMP] old [COMP]

Δ% = ( [1] – [2] ) / [2] * 100

[ x ]  (enter a valid number)
[ x ]  (enter a valid number)

Example:  new = 52, old = 50.  Result:  Δ% = 4

EC 4036 Program: Convert from Rectangular to Polar Coordinates

This converts rectangular coordinates (A, B) to polar coordinates (limited).

r = √(A^2 + B^2), θ = atan(B/A), -90° ≤ θ ≤ 90°

[ x ]  (enter a valid number)
[ 2nd ] [ A >A ]  (store in register A)
[ x ] (enter a valid number)
[ 2nd ] [ B >B ] (store in register B)
HALT  (display r)
[B >B]  (recall B*1)
[A >A] (recall A*1)
HALT   (display θ)

Example:  A = 3.5, B = 3.0. 
Results:  r = 4.609772229, θ = 40.60129465°, 0.708626272 radians

EC 4036:  Circumference and Area of a Circle

This program stores radius in register A and calculates the circumference and area of a circle.  Here I demonstrate the multiplication feature of [A >A].

Circumference = 2*π*r, Area = π*r^2

Input:  radius [COMP] display circumference [COMP] display area

[ x ]  (enter a valid number)
[ 2nd ] [ A >A ] (store in register A)
HALT (display circumference)
[A >A]  (multiply π by register A)
[A >A]  (multiply A*π by register A)
HALT (display area)

Example:  r = 5.45. 
Results:  Circumference = 34.24335992, Area = 93.31315579

This blog is property of Edward Shore, 2017

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