Monday, September 3, 2018

Retro Review: Texas Instruments TI-36X Solar

Retro Review:  Texas Instruments TI-36X Solar

Continuing on the Labor Day 2018 of posts, I now present a retro review of a scientific calculator I couldn’t put down as a young student: the TI-36X Solar. For the class of non-programmable solar scientific calculators back in the day, the TI-36X was the one of the high end calculators. 

If you are expecting a review of the multi-line (and current) TI-36X Pro, then please click here:

General Information

Company:  Texas Instruments
Type:  Solar Scientific Algebraic (postfix)
Display:  10 digits with 2 digit exponents (power of 10)
Power:  Solar
Memory:  3 (store, recall, sum (M+), exchange)
Years:  1991 - 2011
Original Cost: $15 - $20
Documentation:  Manual, Quick Reference Card

Texas Instruments no longer manufactures new TI-36X Solar calculators, so if you want one, pawn shops or internet websites such as eBay would be the place to get one.


* Logarithmic and trigonometric calculations
* Base conversion and Boolean logic
* Linear Regression (intercept is labeled ITC, slope labeled SLP, correlation labeled COR)
* Fractions with conversion and improper fraction conversion (automatic simplification)
* Combinations and permutations
* Eight Scientific Constants and Ten Metric-US Conversions

Scientific Constants ( [3rd], (CONST), appropriate key)

C:  speed of light
g:  Earth’s gravitational constant
me: Mass of an electron
e:  electron charge
h:  Plank’s constant
Na:  Avogadro’s constant
R:  Ideal Gas Constant
G:  Universal Gravitational Constant

Metric-US Conversions

Centimeters/Inches  (1 in = 2.54 cm)
Liters/Gallons  (1 gal = 3.785411784 L)
Pounds/Kilograms (1 lb = 0.45359237 kg)
Fahrenheit/Celsius Temperature
Grams/Ounces (1 oz = 28.34952313 g)

The Exchange Key ([x<>y]) key does a lot  

The TI-36X makes good use of the exchange key, and it is a non-shifted key which facilitates easy operation.  In addition in allowing users to interchange arguments (i.e. switching the subtrahend and minuend in a subtraction calculation), the exchange key allows for:

* Entering n and r in combination and permutation calculations
* Entering x and y in Rectangular to Polar conversions
* Entering r and θ in Polar to Rectangular conversions
* Entering x and y in paired-data statistics (linear regression)


DEC:  Decimal representation, floating decimal mode, normal calculations
BIN, OCT, HEX:  Binary, Octal, Hexadecimal integer modes, respectively.  Boolean functions such as AND, OR, and NOT only work in these integer modes
STAT 1:  1 Variable Statistics
STAT 2:  2 Variable Statistics/Linear Regression

TI-36X Solar:  1991 keyboard, 1996 keyboard, 2004 keyboard

Keyboard Design and History

The design of the keyboards of the TI-36X Solar evolved over the years.  The first major design was rectangular, most of the keys were black with light font.  The arithmetic keys were at first dark gray, then blue.  This was the shortest keyboard in length.  The calculator had a slide hard case.

Then in 1993, the TI-36X Solar had a keyboard with a rounded edge at the bottom of the keyboard.  The 1996 version is slightly longer in size, with the yellow 2nd key and blue-purple 3rd key.  Constants were labeled in green. 

The final design of the TI-36X came in 2004, with an even bigger keyboard.  This time the keyboard was silver with the royal blue 2nd key, lime green 3rd key, and constants marked in maroon.  This is the most readable keyboard, however the 2004 version needs more light to operate than its previous versions.  This version also had a snap on case. 

With the exception of the 1993 revamp, the keys were plastic.  The 1993 version had rubber keyboards.  The keys generally had a good response to them. 

Of the three TI-36X Solar calculators I have now (just purchased one with the 1991 original style keyboard), the manufacturing dates where 12/1990 (1991 keyboard), 6/2000 (1996 keyboard), and 6/2010 (2004 keyboard). 

TI-35X, the battery operated version of the TI-36X Solar, 1993 keyboard with rubber keys

The TI-36X Solar had a battery operated version, named the TI-35 Plus.  I have a TI-35X in a 1993 version keyboard with the rubber keys. 

The TI-36X Solar was itself a successor to the TI-36 Solar.  The TI-36 Solar lacked constants, English-US conversions, fractions, and linear regression, but had complex number arithmetic. 

The successor the TI-36X Solar is the TI-36X Pro, which has a multi-line screen, adds among other things, integration, derivatives, function tables, textbook input/output, matrices, and additional regression types.

My introduction to the TI-36X Solar was when in I was in middle school back in the early 1990s.  I couldn’t put this calculator down.  I wished I remembered to use the hard cover because one day I had the TI-36X Solar in my pocket with a pencil.  The pencil poked through the solar panel and it was the end of it. 

The TI-36X Solar is a feature rich scientific calculator and as I said before, one of the line non-programming solar scientific calculators at the time.  The keyboard is responsive, you have a nice set of common constants and conversions.  I like the layout of the keyboard.  This is a good calculator to pick up, even if it is just for collection purposes.   For a retro calculator, the TI-36X Solar is a definite recommend from me. 


Woerner, Jorgen.  “TI-36X Solar” Datamath 


All original content copyright, © 2011-2018.  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.  Please contact the author if you have questions.

Casio fx-5000F: Auto Formulas

Casio fx-5000F:   Auto Formulas The formula listing can apply to (almost) any calculator that can handle formula programming. In November, t...