The new TI-84 Plus C Silver Edition isn't the first color-screen graphing calculator. It isn't even TI's first color graphing calculator, a distinction claimed by the TI-Nspire CX and its sibling the TI-Nspire CX CAS. However, the TI-84+CSE, as we're abbreviating it, is a major milestone in the 17-year-old TI-83 and TI-84 Plus family of calculators. Although it retains the look and feel of the TI-84 Plus operating system, and keeps the familiar case shape and key layout, the outstanding feature of the TI-84+CSE is a bright, glossy color LCD screen. No longer will math and programs need to squeeze into 96 by 64 monochrome pixels; the new screen is 320x240 and can display 65,000 different colors.

Starting in November 2012, Cemetech first discovered and received official and unofficial updates about the new calculator. We've seen a seminar showcasing the math features and gotten the official PR information. Now, we're proud to announce the first full, formal hands-on review of the TI-84 Plus C Silver Edition.

*Following is the most in-depth look at a graphing calculator we've ever seen, compliments of Christopher Mitchell at Cemetech. Read it, learn something, and be amazed.*

Our TI contacts sent yours truly, Cemetech administrator Christopher Mitchell, a preview calculator, the very device pictured above. I have spent hours engrossed in trying out its many new math and programming features, and my first impressions as a fourteen-year user of TI's graphing calculators is overwhelmingly positive. In this complete review, I'll show you the new math features, as well as the existing features that have been augmented with the color and higher resolution the new LCD affords. Since my real passion for TI calculators lies in programming, I'll also show you the new features for TI-BASIC programmers, and discuss some of the new discoveries that assembly programmers need to know. Finally, I'll do a quick teardown of the device, so that you can see what makes it tick. In a phrase, the new TI-84 Plus C Silver Edition is sleek, colorful, and takes good advantage of its new hardware, marred only by slight (easily-fixed) sluggishness.

**Physical Features**

The TI-84 Plus C Silver Edition has the same case and keyboard as its predecessor, the TI-84 Plus Silver Edition. It has a serial I/O port and a miniUSB jack at the top of the case, the LCD taking the upper one-third of the front, and the keyboard occupying the remainder. Like the TI-84 Plus Silver Edition, it has interchangeable faceplates, although I suspect many students will choose to keep the glossy black faceplate included with the calculator. The largest changes are the new color LCD and a rechargeable Li-Ion battery replacing the old AAA battery compartment. It has a few smaller changes: a charging LED on the top of the right side of the device, used to indicate whether the device is charging or charged, and two contacts on the lower sides of the devices for charging in a cradle. The calculator ships with the miniUSB cable and calculator-to-calculator USB cable that all TI-84 Plus calculators have included, but my review calculator also included a wall-to-USB power adapter for computer-free charging. TI claims that the battery is good for about a week of in-class use or 2 weeks of homework, and my unit seemed to last around 8-10 hours of use on a charge (in a very unscientific test).

Turn the calculator on, and you're confronted with a new but familiar-looking view. While you still have a homescreen for doing math and calculations, a new bar is present at the top of the LCD displaying the calculator's current modes as well as a battery meter. No matter where you go in the OS, that status bar follows you around. A quick trip around the menus would soon show you that almost everything is where you'd expect from using a TI-84 Plus Silver Edition. You can still do math, statistics, graphing, and programming. You can still work with lists and matrices and tables of graph coordinates, albeit on a larger screen. While the older calculator models could all show 8 rows and 16 columns of normal-sized text at once, the TI-84+CSE fits 10 rows and 26 columns of text. Let's go deeper into what you can do with all this space with a look at the math features.

**Math Features**

The TI-84 Plus C Silver Edition, for all its fanciness, must at heart be an effective tool for math. To evaluate whether it succeeds, we must look at a few factors. First, will the legions of students and teachers accustomed to learning with the TI-83 Plus and TI-84 Plus be able to adapt to this device? Second, will users who pick up the calculator for the first time find it easy to use? Finally, does it keep all of the features that made the TI-83 Plus and TI-84 Plus overwhelming successes while effectively exploiting its color screen to make math even more understandable? In this reviewer's opinion, the answer to all three is a resounding yes. That enthusiasm would be slightly qualified if you look at the calculator as more than a pure math tool, but we'll get to that later.

Arithmetic and Algebra: For the first question, the interface will undoubtedly be comfortable for students and teachers comfortable with TI's other TI-83 Plus and TI-84 Plus calculators. Although menus hold more text and the graphing features have been overhauled, for the most part everything works the same. The calculator has a MathPrint operating system, which means that as on the recent TI-84 Plus and TI-84 Plus Silver Edition calculators, radicals, exponents, functions, and fractions look a lot like what you'd expect to see in a math book. The left side of Figure 1 shows some calculations on the homescreen with the new higher-resolution MathPrint. Unfortunately, TI doesn't take advantage of the color screen to highlight matching parentheses (a feature found on the Casio Prizm), but that's a trivial complaint. The new calculator will be no more or less easy-to-use to new users than the existing models, which is to say relatively simple (for the simpler features). Some features, especially statistics, have been made even easier, as you'll see. How about effective use of the color LCD? Let's look at graphing to answer that.

*Figure 1: Homescreen MathPrint math equations (left) and the new graphscreen (right)*

**Graphing:** As you can see from the right side of Figure 1, graphing has gotten a lot fancier. Due to technical limitations (CPU speed and RAM), the graphscreen is 265 pixels wide and 165 pixels tall, with a thick border around the edges. Equations and statistics plots can now be graphed in any of 15 different colors, various line styles, and with even more shading options than the older calculators. Because we're no longer limited to black-and-white, it's now much more useful to put a grid of lines or points behind graphs so that you can easily figure out coordinates of points on a graph. Therefore, the three new grid options are GridOff, GridLine, and GridDot. You can set the grid color, the axes color, and the color of the border. Perhaps the most novel feature is the ability to put a photograph ("Image") behind the graph, although since we do not yet know the Image format we were unable to test this feature. There's a feature to detect asymptotes, which will make tangent graphs (for one) much more understandable. Overall, the graphing feels much more powerful than on previous models, and isn't appreciably slower (nor faster).

*Figure 2: Shaded graphs (left) and some polar spirographs (right)*

**Statistics**: All of the new Stats Wizards from the MathPrint operating systems are present on the TI-84 Plus C Silver Edition, in more or less the same form as on the previous black-and-white TI-84 Plus calculators. There is, however, a new mode called QuickPlot&Fit-EQ. If you choose this option from the Calc tab of the Stat menu, you'll be taken to the graphscreen, where you can move the cursor around and create a series of points to represent a scatter plot. As with other drawing modes, there's a Style menu accessed via [F5] ([Graph]) to control the color of the points you drop. When you place at least two points, the Style menu changes to a FitEQ menu: select it, and you'll get a list of the types of equations you can fit to the points you placed. The calculator will find the line of best fit, draw it, and show the equation for the resulting graph. This new mode will greatly simplify the task of fitting lines to sets of points, which previously took three tedious steps.

**Drawing:** The Draw menu ([2nd][PRGM]) has a new Background tab, but the real difference comes when you go to draw on the graphscreen. Invoking any of the drawing functions like Line, Pt-On, Circle, or Text will take you to the graphscreen, display a cursor, and place the aforementioned Style menu in the lower-righthand corner. From the menu, you can change line color and thickness, text color, and point color and style. While the new Image feature is used for full-color photographs, you can use the old StorePic and RecallPic to save and recall 15-color snapshots of the graphscreen. Because each of the Pic variables is now 22KB, they can only be stored in archive, and are (understandably) slower to save and open.

**Programming Features**

Like the TI-84 Plus Silver Edition and friends, the new TI-84 Plus C Silver Edition can run TI-BASIC and z80 assembly programs.

**TI-BASIC:**

I bet the programmers among us were as anxious as myself to know whether the existing TI-BASIC programming features were retained, and the answer is a resounding yes. In addition, TI-BASIC programs can access all of the new drawing function in their 15-color glory, from lines and text to points and pictures. Check out Figure 3 for an animated screenshot of different line thicknesses, text sizes and colors, and point styles. The right side of the same figure demonstrates that the Output( command can address every row and column of the new 10x26-character homescreen. We have already found a bug in the Menu( command, and unusual behavior with non-black Pt-On( commands, but we anticipate being able to work with TI to resolve these and any other issues we find.

**z80 Assembly:** For assembly programmers, all existing programs and Apps will have to be ported to the new calculator. Programs are placed at a new address, the AsmPrgm token has been replaced by an Asm84CPrgm token, and most bcall and safeRAM addresses have changed. The biggest difference is that because it is impossible to store a 150KB LC buffer in RAM, coders will have to re-think how they use the screen. We have been extensively discussing best practices for 84+CSE ASM programmers and porting existing apps like Doors CS here at Cemetech, and we hope the programmers among us will join the discussion.

**Hardware Teardown**

No Cemetech review of a new calculator could be complete without a look into the hardware. If you look at the photograph below, you can see, from left to right, the slide case, the rechargeable battery with the case screws and the battery cover, the back cover, the antistatic shield covering the mainboard, the mainboard itself, the key membrane and keys, the black faceplate, and the front cover. Unfortunately, because the LCD is glued onto the other side of the mainboard, I was unable to detach it for fear of cracking the glass. The major features on the mainboard are a 4MB (32Mb) Macronix Flash chip, a custom TI z80 CPU/ASIC that exactly matches the one in the TI-84 Plus Silver Edition, the USB and I/O ports, and ancillary support components. The LCD driver, the ILI9325, is presumably a chip-on-glass device on the underside of the LCD. Hardware-wise, this is a very minimal departure from the TI-84 Plus, the only real differences being the battery, 4MB Flash chip, and color LCD. It turns out that all of the CPU/ASIC-specific features to support the TI-84 Plus C Silver Edition were actually already present in the TI-84 Plus years ago, which explains several mysterious, unexplained, and unused features that were discovered back then. Although we will continue to research the ASIC and the LCD, we don't anticipate any big surprises.

**Summary: The Big Picture**

As I prefaced this review, the most important question I have to ask is whether the TI-84 Plus C Silver Edition is an effective math tool. In a world where students are increasingly distracted by complex, flashy smartphones that are indistinguishable from tiny computers, and where TI's black-and-white calculators have been increasingly noted as antiquated, this is a huge step forward. From the perspective of a math student or teacher, this is a calculator that combines an easier-to-read, more expressive display that can show graphs and equations more easily with a familiar interface. All of the existing books and tutorials on the TI-83 Plus and TI-84 Plus apply to this new calculator, although it behooves new references (like my own TI-83+/TI-84+ math book coming soon) to explain and explore the new features like color graphing and Quickplot&FitEQ. The interface feels slightly sluggish, with some menus taking close to a full second to fully render, which hopefully won't discourage impatient students from using the device. From a programmer and enthusiast point of view, my reaction is more mixed. There's a prevalent opinion that something like a 25MHz ez80 CPU, a faster, more capable, and fully-compatible version of the processor in the new (and old) calculators, would have been a better choice. A CPU clocked at close to twice the speed would have helped reduce the lag in rendering complex menus and large images, and would have given programmers more options for creating quick, responsive programs. Nevertheless, I know that many ideas are already being tossed around to work with the capabilities that the new calculator does have, and I'm sure many among us will rise to the challenge.

At a rumored $129, the new calculator is around the same price-point as the TI-84 Plus Silver Edition, and about $10 more expensive than its color-screen competitor, the Casio Prizm. I think it's a good investment for any student looking to get a new graphing calculator, and not a bad choice for programmers to explore as well. The OS feels stable and remains full-featured, the slight LCD sluggishness can be excused for math, and we look forward to years of continued progress in the TI-83 Plus/TI-84 Plus family! For more specs, references, history, and information on the TI-84+CSE, please refer to our TI-84 Plus C Silver Edition reference page. Thanks to DrDnar, BrandonW, calc84maniac, critor, Tari, and all the other people who have contributed their brains to the technical exploration of critor's calculator.

*This post originally appeared on Cemetech. Cemetech is a software and hardware community teaching programming and showcasing projects from students, enthusiasts, and professionals. It focuses on graphing calculator programming, but covers computer, web, and mobile programming, as well as DIY hardware. Besides its active discussion forum, Cemetech offers tools like an online graphing calculator emulator and programming IDE, and an archive of freely-available software.*

*Christopher Mitchell** is a teacher, student, and recognized leader in the TI-83+/TI-84+ enthusiast community. He is currently pursuing a PhD in distributed systems, and has spent 14 years sharing his enthusiasm for programming and answering programming questions on his website, Cemetech.*