If there’s one company that can take credit for developing the hand-held calculator, it’s Texas Instruments. They’re not just known for the calculator, though – TI was responsible for many innovations over the years, including the first silicon transistor (1954), the first transistor radio (1954), the first integrated circuit (1968) and even the first LPC speech synthesizer (1978).
Still, for years, TI was associated with calculators, starting with the popular SR-10 (1973) and SR-50 (1974) models. We’ve come a long way from the days of those heavy, clunky and expensive hand calculator – for higher math and scientific work, the TI-84 is now one of the go-to calculators on the market.
The TI-84: Loaded With Features
Released in 2004, the TI-84 Plus is a graphing calculator that superseded the TI-83 Plus model. As an enhanced version of the TI-83 Plus, the TI-84 Plus is similar in operation but does feature some improvements in hardware. The CPU is more than twice as fast, with a ROM archive that’s about three times as large. The TI-84 Plus’s USB port is USB On-The-Go compatible, a feature it shares with the next-generation TI-Nspire calculator.
Versions of the TI-84 Plus
TI-84 Plus Silver Edition: This upgrade to the TI-84 Plus was released in 2004 and features a 15 MHz Zilog Z80 processor with 24 kB user available RAM. It features a robust 128 kB chip (48 kB on newer models) and 1.5 MB f user-ready Flash ROM. Like the base model TI-84 Plus, the TI-84 Plus Silver Edition features a built-in USB port, built-in clock and assembly support.
TI-84 Plus CE and TI-84 Plus CE-T:Introduced in 2015, these two variants on the TI-84 Plus feature a rechargeable battery and 320x240 pixel color screen, with 154KB of user-accessible RAM and 3.0MB of archive memory. It uses Zilog’s eZ80 processor and is programmed in English, French, German, Portugese, Spanish and Swedish. This education market-oriented calculator comes in colors that include Classic Black, Silver Linings, Positively Pink, Radical Red, True Blue, Denim Blue, Plum Pi, Golden Ratio, Bright White and Lightning Blue.
Software for the TI-84 Plus
The TI-84 series of calculators uses three different programs, easily programmed or downloaded into the calculator: TI-BASIC, Flash applications and Z80 assembly language (compatible with Flash). The exception is the TI-84+CE, with programs written in TI-BASIC, eZ80 assembly language or C programming language.
TI-BASIC: This proprietary software is similar to the BASIC programming language that’s been in use for PC machines for decades. It’s one of the most direct ways to program any TI calculator, but it’s slower than assembly language. It’s a better fit for performing repetitive calculation tasks or writing programs for solving math problems, rather than graphics-intensive applications or programming games. Its syntax is somewhat different from BASIC, with a character set that’s somewhat non-standard (such as all statements beginning with a colon, square and cube roots and other mathematical symbols).
Assembly language: Like with other machines, the TI-84 Plus’s assembly language is a low-level programming language with a strong relationship between assembly program statements and the machine code instructions of the architecture itself. In other words, an assembly language is more specific to the architecture of a particular computer, where high-level programming languages are portable across different architectures (but might require interpretation or compiling).
C: Developed in the early 70s, C is designed to re-implement the Unix system and has become one of the most prevalent programming languages of all time. It’s compatible with all types of computer architectures and can be found on everything from supercomputers to embedded microcontrollers.
USB On-The Go Feature
USB On-The-Go is a technology that you’re probably familiar with but haven’t ever given much thought to. Introduced in 2001, USB On-The-Go allows tablets, smartphones and other USB devices to be compatible with digital cameras, mice, keyboards, flash drives and other devices. Its design allows the devices to switch back and forth and alternate between the roles of host and device – for instance, a mobile phone can operate as a host device when it’s reading from removable media but serves as a USB mass storage device when it’s connected o a host computer.
This is an especially handy feature when you want your TI-84 Plus and PC to talk to each other:
Run a cable from your calculator’s mini-USB port to the USB connector on your computer
Press o after connecting, which will allow the computer to recognize the action of turning the calculator on
You should see the TI Connect home screen, with a Select TI Device dialog box
Click on your device in the dialog box, then click the Select button
Storing a Number as a Variable
For many math functions, you’ll find yourself using the same number over and over, which makes it a good idea to store that number as a variable on your calculator. Here’s how:
Press [2nd] [MODE] to access the home screen
Enter the number you want to store as a variable, which can also be stored as an arithmetic expression. The calculator will evaluate that expression after you’ve taken all the steps for storing the number
Press [ALPHA] and then press the key that corresponds to the letter of the variable that you’d like to assign to the number
Press [ENTER] to register and store the variable
NOTE: with graphing functions, polar equations, parametric equations and other operations, the calculator might change the value of the variable when the calculator is in graphing mode. For instance, if you were to store a number as variable X and then asked the calculator to determine the zero of the graphed function X2, the calculator will replace the number of that X variable with a 0, which would be the zero of X2. Be mindful of this for certain operations.
After the number has been stored as a variable, it can then be used in an arithmetic expression. Just place the cursor where you want the number to be assigned in the math problem, press [ALPHA] and press the key that corresponds to the variable of the number you want to use.
Using the TI-84 Plus For School And Tests
Viewing graph and table at the same time: This is a pretty handy feature for many situations. Just press y= and type the equations. Next, press the mode key and you’ll see a row on the screen that says FULL HORIZONTAL GRAPH-TABLE. Use the arrow over to GRAPH-TABLE, then press enter. Next, press the graph key to see graph and table simultaneously. Press the 2nd key followed by the graph key to access all the values in the table. To exit from this view, press the mode key and select FULL.
Using lists to investigate transformation graphing: Press the stat key and select the first option. In the list L1 enter -2, -1, 0, 1, 2. Next, press the y+ key. To get L1, press the 2nd key followed by the stat key. You’ll see L1 as the first option. You can then change your equation in Y1 to explore.
Storing window setting: You’ll find instances where it’s really handy to store your favorite window setting so you can recall it whenever you need. Just press the window key, then change the window setting values to reflect what you need to store. Next, press the zoom key and use the arrow over to MEMORY. Next, just select ZoomSto and press enter. This will store the setting until you either reset the calculator or need to store a different window. To recall and use this setting, press zoom, then arrow your way to MEMORY and select ZoomrRcl.
Using the TI-84 Plus for ACT Testing
The ACT puts strict prohibitions on which calculators are permissible during tests. Any calculator with built-in algebra systems (which rules out the TI-89 and TI-Nspire), laptops, tablets, cell phone calculators, calculators with a QWERTY keyboard and other types are prohibited. Using one of these machines can actually get a student thrown out of the test. Test proctors will warn students about this at the beginning of the test and will collect any prohibited calculators – sometimes leaving students to work out all problems by hand.
The TI-83 and TI-84 Plus, however, both fall into the graphing calculator category that’s permissible for this test. Educators want to stress, however, that what calculator a student chooses to use isn’t what’s important – it’s the information that’s put into the calculator and how the student uses that information.