Definition:
The TI-30X IIS, is a solar powered scientific calculator. Though there are many kinds of calculators, which can serve many different functions in areas of mathematics, the TI-30X IIS falls under the category of a four function calculator. This means that this calculator is limited by its abilities and can only add, subtract, multiply, divide, take square roots, and percentages. The calculator is ideal for pre-algebra, algebra, geometry, statistics, and general sciences. The calculator is used on a plethora of standardized examinations including, but not limited to the SAT, ACT, and AP exams in high school. The calculator also serves as a means of calculations in college level general science classes and beyond.
Overview:
In a mere two years, a group working at Texas Instruments, Jerry Merryman and James Van Tassel, and led by Jack Kilby developed a small handheld calculator. Since then the model of the Texas Instrument calculator has been improving with technology. The inception to a long line of scientific calculators leading up to the TI-30XIIS was the TI-30 which led to a series of TI-30 calculator models. The TI-30 was the first model introduced in the 1970’s but discontinued in the early 80’s. After being discontinued the model went through several design revisions, which included the use of a liquid crystal display to keep up with the advancing technology.
Contrary to the gray monochrome colors seen on the liquid clear display today the color of the text on the display was red. The original and updated models of the TI-30 series had all of its mathematical functions rely on a chip in the circuit board. The TI-30 series offered an affordable option for a mathematical computational device in the 1980’s and even now. Throughout the recent years the TI-30XIIS has displayed some advancement with the integration of solar panels and minor changes in display technology.
The calculator comes in various colors, independent of any internal functions. The model has a two line display. There are forty-four keys all indicating numbers, trig functions, and numerical operations. The design is simple and the device is lightweight. The calculator weighs approximately 136 grams which is slightly lighter than graphing calculators, which usually weigh around 190-220 grams. Its two line display made of a liquid crystal display allows users to easily read what is on the screen. The TI-30X IIS model costs around $17.00 to $20.00, varying across different websites.
Exterior Components:
Input buttons:
The TI 30X IIS features a distinct set of input buttons designed to compute very basic mathematical calculations. The buttons are placed flat on the front write below the liquid clear display. Above some buttons there will be another option to input and those can be accessed with the use of the “2nd “ button. The list below describes all buttons present on the model including the function of each button.
- Numeric buttons 0-9 are used for the input of numbers.
- Buttons indicating symbols: +, -, x , ÷ which are for addition, subtraction, multiplication and division.
- “ ^ ” button which raises a number to any power.
- “ 2nd ” button turns on the 2nd indicator and accesses the function shown in the image above the key you press.
- “LOG” and “LN” buttons compute logarithms.
- Trigonometric functions sine , cosine, and tangent are denoted on the buttons as “ SIN” , “ COS” and “TAN” .
- Buttons “(“ and “)”input open and close parenthesis.
- “ x-1” button inputs the reciprocal of a numerical input.
- “⏴”, “⏵” buttons move cursor to left and right
- “⏶”, “⏷” buttons move cursors up and down to see previous entries of input
- “x2” button squares input
- “” button inputs constant pi (3.14……)
- “ ” button inputs a decimal point
- “(-)” button makes a an inputted value negative
- “ ° ‘ ” ”, button displays a menu that specifies the unit of a certain angle.
- “ Abc” button allows inputs for mixed numbers and fractions.
- “=” button completes an operation inputted
- “DEL” button deletes input wherever cursor is
- “DRG” button allows you to change angle to radians, degrees, or gradients
- “DATA” button allows you to answer statistical data points
- “STATVAR” button displays a menu with options for stat variables
- “CLEAR” erases inputs and error messages on the screen
- “STO⏵” button button displays the following menu of variables: “A B C D E” and “rand”. “Rand” allows you to set a seed value for random values. “A B C D E” lets you replace stored values.
- “MEMVAR” button displays the following menu of variables: “A B C D E” lets you paste the stored value before inputting it on the display.
Figure 1:
Input buttons along with other functions printed in light blue on top
Liquid Crystal Display:
The TI-30XIIS includes a Liquid crystal display, visually outputting information. The liquid crystal display puts into use the light modulating properties of crystals and polarizes them in order to produce images without emitting light directly. There are multiple layers within the liquid crystal display in order to manipulate reflected light and create images. These liquid crystals cannot produce light themselves so a reflective backlight is needed to create a reflection, which produces light waves. This allows light to be absorbed through all the layers of sub-pixels allowing us to see the grayish-black numbers punched in our calculator.
Figure 2:
Figure 2(above): Liquid crystal display to see inputs
Solar Panel:
A small solar panel is present in the model. The small solar panel contains PVC cells, where silicon atoms are present and release electrons when sunlight is absorbed. The solar panel is located on the front of the calculator and is right above the liquid crystal display. The reasoning for this placement is that is where the panel can absorb the most light. These electrons create an electric current, which in turn powers the calculator. An electric field is created maintaining the three volt lithium battery. This eliminates any need for external charging with a wire and outlet.
Figure 3:
Solar panel on front of calculator
Interior Components:
Three Volt Lithium Battery:
Three volt lithium batteries are primarily used to power small electronic devices, some medical devices, and toys. These batteries typically last for three-five years on average. The battery consists of an anode, cathode, separator, and an electrolyte. Lithium ions flow from the anode to the cathode going through the electrolyte and separator. The charge changes direction and the ions flow from the cathode to anode. Free electrons are created from this movement of lithium ions and those free electrons generate a positive charge. The constant movement of the ions creates an electric current, which then powers the calculator.
Figure 4:
Parts of the lithium ion battery that work to create an electric current
Figure 5:
3-volt Lithium battery on the circuit board
Circuit Board:
All the following components that will be described come together making the circuit board. Like most scientific and four function calculators, integrated circuits are present. A double sided PCB circuit board is used in this calculator model. One side of the circuit board allows for the visual functions of the liquid crystal display to work, the other side of the PCB board contains transistors and has the keypad where signals are generated based on which of the forty-four keys present on the calculator are pressed. The circuit board is made with layers of copper and conducive wire, which work to power all the other components.
Figure 6:
Figure 6 (above): Entire circuit board
Transistors:
Transistors are computing devices, which physically act as light switches, however in the device they are used to represent numbers and different inputs. The TI-30X IIS has over thousands of transistors that switch on and off, creating instructions for mathematical operations. When a button on the calculator is pressed a circuit is completed and a signal is sent to the transistors, which create an electrical impulse allowing functions to be computed on the calculator.
Figure 7:
Circled in black is the transistors present in the circuit board
Diodes:
Diodes isolate flows of electrical signals toward a certain direction. The diodes ensure that all internal components receive a consistent and stable supply of direct current. Due to diodes isolating the flow of electrical signals, they also ensure that there is no reverse voltage, protecting the power source from any potential damage.
Figure 8:
Diodes on the circuit board
Electrolytic Capacitors:
Electrolytic capacitors prevent ripple voltages and couple signals in the calculator in order to filter out direct current power from solar power retrieved from the solar panel. A high level of ripple voltage can lead to instability and burn out in the device. The electrolytic capacitors ensure there is a smooth transition from alternating current to direct current power supply entirely using solar energy absorbed from the solar panel’s PVC cells.
Figure 9:
The ‘C’ present in the label is for capacitor
Touch Activated Electrical Circuits:
Capacitive touch switches are present which detects when the buttons of the calculator are pressed. The circulation of electricity and signals omitted are restricted until a button is pressed. The touch activated electrical circuits are circular and look like little holes which are connected to extensive wiring. The circuits are connected to the circuit board through wiring tape.
Figure 10:
Touch activated circuits within TI-30XIIS
The Chip:
The chip is located on the circuit board near the transistors and is covered by a black latex and rubber coating. The chip is where most of the mathematical computation is done in the TI-30XIIS. The chip consists of components such as ALU, an arithmetic logic unit, which processes instructions for arithmetic calculation. The chip also sends out signals to other parts of the calculator to coordinate responses of outputs. This chip is essentially the entire ‘brain’ of the calculator.
Figure 11:
The arrow is pointing to a large black spot, which is epoxy covering the chip
Conclusion:
The texas instrument TI-30X IIS is a technological and mathematical tool that has allowed for easy and convenient computation within different grade levels and schools. What started out as an LED display gradually led to a more technologically advanced liquid crystal display that is energy efficient and long lasting.
The need for calculators is crucial in the fields of mathematics and the sciences as it enhances accuracy, provides aid in solving more challenging mathematical equations with larger numbers, which can take time to solve by hand. The stress in performing tedious calculations with long and arduous constants such as Avogadro’s number ( 6.023 1023 ) has been alleviated through the use of convenient hand held calculators such as the TI-30XIIS.
The TI-30X IIs use of solar power has prolonged the life of the device, allowing students to carry them around for longer and use them for longer periods of time allowing users to rely on their calculators for longer periods of time.
References
Ahmad, A. A. (2024, April 15). Figures-11. Google Slides.
https://docs.google.com/presentation/d/1f-uOGnMpV3FVftQ0YVlAjgjaVDnikWDX9zYTKrx8MhU/edit#slide=id.p
Centre for Computing History. Centre For Computing History.
https://www.computinghistory.org.uk/det/31286/TI-30-Scientific-Calculator/
Complete guide to push button switches by Eaton. RS. (2023, November 27).
https://uk.rs-online.com/web/content/discovery/ideas-and-advice/push-button-switches-guide
Handheld Electronic Calculator Prototype – Texas Instruments Cal Tech. | National Museum of
American History. (n.d.). https://americanhistory.si.edu/collections/nmah_1329686
TI30X-IIS calculator quick reference keys sheet. (n.d.).
https://www.hopewell.k12.pa.us/Downloads/quick%20reference%20keys.pdf
{{productdata.name}}. 25465103 – Online Store. (n.d.).
https://sellugsk.live/product_details/25465103.htm
Reflection:
This assignment has been quite different from anything I have ever done before. I have read several manuals for things such as furniture to game consoles, but I have never dabbled in the arts of creating one. This assignment, although challenging, allowed me to hone on my technical writing skills. The technical description was a completely objective piece with a clear cut way of writing it.
Throughout my completion in this assignment I was able to “Engage in genre analysis and multimodal composing to explore effective writing across disciplinary contexts and beyond”. As previously stated this type of writing was and still is completely new to me. I was able to break down the parts of a manual and analyze the importance of each part. Contrary to a lab report a manual is not trying to convince anyone that their scientific findings and discoveries are relevant and hold true in the world of science. Instead the manual visually takes apart the mechanism of the object and describes the function of each part. Similar to a lab report, however, a manual also has a certain structure it follows, so that it makes sense. For instance, describing the exterior and then interior parts allows readers to get a better idea of the object as a whole.
Additionally, I was able to hone my research skills. From my collection of different sources found through browsers such as google scholar and the CCNY database I was able to locate sources easily and integrate what I needed from them in my manual. The skill of researching and finding sources is incredibly essential as it makes your credibility much stronger. However, finding sources was quite difficult as most of the manuals I had found for the calculator model I took apart had been only describing the functions of the input buttons and the mathematical computations the device could do, rather than explaining how the specific circuits and batteries work. This manual overall allowed me to tap into a different side of my writing and included a hands on part, which I enjoyed.
