Texas InstrumentsTI-89 Titanium Graphing Calculator (packaging may differ)

I bought the TI-89 Titanium to be compatible with a fellow engineer--it is great to be able to share code and math solutions for the same model of calculator. This is a switch for me, since I have always been a Hewlett-Packard fan. I have at least one of almost every model of HP graphing calculator, and many other models, going all the way back to 1972 and the HP 35. It never occurred to me that the TI-89 series could actually be competitive with HP. Well, it is! This calculator has some very nice features, and a few features that the similarly capable HP 49G does not. I'll leave it to the buyer to explore the manuals and figure some of that out for themselves. But I will definitely note that the Home screen edit/command line has superior behavior in several ways to the HP 49G. One of those is the retention of the last problem, equation or expression entered by the user. That means you can simply solve the first problem, then move the cursor around in the problem, replace a variable, change a sign, or make any other edit needed to evaluate the problem in different ways, without having to copy the equation/expression from the history (as you would have to do with the HP 49G).The HP 49G has more memory than the TI-89 Titanium (mine is a HW4 edition), and a more feature-rich file system (more like a PC). TI partially compensates for simpler filesystem by having apps show only files appropriate for the app you are using at the time, which helps avoid visual clutter. The TI-89 Titanium has a lot of useful, very high quality apps, preinstalled.Both models have a CAS and about 800 scientific functions, constants, and unit conversions but, while unit conversions are faster and easier on the HP 49G, unit math is better on the TI 89 Titanium if what you expect the calculator to do is simplify units to the most practical SI or SAE unit. As an example, if you multiply 200,000_Pa by 1_l, the simple answer is 200e3_Pa*l, but the most practical SI unit resulting from that product is the Joule. The TI-89 Titanium correctly substitutes units and answers with 200e3_J, while the HP 49G (and later RPL graphers) renders the easiest, but least helpful, answer of 200_kPa*l--the correct answer, but left in inconvenient units. (The 49G does have the advantage of having metric/engineering power-of-3 prefixes, such as k, M, G, m, n, etc.)In a way, the TI-89 series is as much a personal digital assistant (PDA) as it is a graphing calculator. This is the result of having numerous useful record-keeping applications, a clock/calendar, event scheduler, task manager, personal contact database, etc. The Titanium also comes preloaded with EE*Pro, a professional-quality problem solver app aimed primarily at electrical engineering professionals. The closest preloaded application HP shipped with a later model of the 49G series, the HP 50g, was a library of powerful equations copied from the HP 48G series, and an interactive Periodic Table of the Elements for chemistry. Don't get me wrong, those are very useful, and the Periodic Table app is better than ones I've seen for TI. But, the TI-89 series was marketed to students and professionals alike as more than just a graphing calculator with a CAS. It is a PDA. In 2020, that seems a silly point to make, given smartphones of today. But in 1999, when both the HP 49G and the TI-89 series were made, the TI appears to have been a better fit for students and, depending on the disciplines, maybe better for engineers. In most respects, the I prefer the HP, but some features of the TI are eye-opening ideas that explain to me why TI is still making graphing calculators for the US market today, while HP has fallen out of the business in the US, even after the release of the formidable and capable HP Prime (which is, in my opinion, superior to the TI-Nspire CX series). TI showed a better design balance with the 89 series, making the flagship graphing calculators fit either the student or the professional technical user, and most apps for the TI-89 series are of very high quality.One more point I will make, is that both are programmable; the TI-89 Titanium is natively programmable in TI BASIC, while the HP 49G is natively programmable in HP Basic and in UserRPL. HP Basic (not BASIC) is limited compared with TI's M68000 BASIC, but HP RPL is more powerful, more elegant, faster for most programs, and more efficient than TI's BASIC. However, TI BASIC is pretty intuitive, while RPL is considerably harder to learn if the user is not already familiar with Reverse Polish Notation and the HP stack or the Forth programming language (and its stack).Overall it is quite a toss up between the two. But if one were to ask me which brand to go with today, my answer would most probably be, "Go with TI. Get one of the TI-Nspire CX models if you are in high school or college and don't plan to use the calculator in a career, but get the TI-89 Titanium if you plan to keep using it beyond school and into your career." I am pleased with the design, speed, and ease of learning on the TI.

My Voyage 200 calculator finally crashed after 20 years, and this calculator can do all or most of what that one did. So, I got it as a replacement. I am in the process of comparing this one with the Ti-NSpire CX CAS calculator to see if there is any difference based on what I do. So far, they are similar though the NSpire has a backlit screen, and the Ti-89 does not. for an old man like me, the lighted screen is a help. So, I find myself reaching for the NSpire a lot as I go through a calculus course. From a technical point of view, they both seem to have similar math capability up through calculus and differential equations.

There isn't alot I can say about this calculator which hasn't been discussed by previous reviewers. I, like the majority of them, and probably you the reader, have an 83 and got into a calculus course, or calculus-intensive course, and realized that the 83 was no longer going to cut it. Well I got the 89 from amazon and since that day the 83 began to look more and more primitive...sigh...The 89 can factor, differentiate, integrate, sum, products, binomials, solve systems and matrix operations, etc. It can also graph in 3d, polar, or differential field (what you may have seen in the promo shots). It even has the option of exact or approximate answers. A very helpful option I've found is the stored units of measurement you can use in the cases where you need to work problems in physics, engineering or even chemistry. After about two months of use I'm still learning just how much this graphic utility has to offer, but the user-interface has long since become completely intuitive for me. But the buyer should beware if they are making the transition to this right before the final--its menu style interface takes a day or so to get used to, and the manual while long isn't as comprehensive or as clear as it could be, relying heavily on abbreviations. Perhaps the most frustrating thing to learn is the exact sequence various commands need to be entered in, in order to get to the graphing utility to something other than say TOO FEW ARGUMENTS or SYNTAX ERROR. (Using the onboard catalog of functions, gives you an entry guide at the bottom of the screen.)What I didn't expect to use, but find very useful is the USB cable and software which allows me to upload screen shots, ie graphs, which I can then attach for homework and lab assignments when I dont have access to either Derive, Excel, or my mac's Grapher. It is also possible to download additional programs and apps but I can't see me, or most of the potential buyers, of this utility actually needing to do this. It can be programmed as well, but again I have hard time imagining when the need to do this would actually arise.This graphing utiltity is a little larger than the 83-85 line (already bordering on the cartoonish) but it is significantly smaller than the 92 (with which it shares the exact same Derive software and which has a full-qwerty keyboard.) However, this is an altogether much more powerful device than the 83 and an equal to the more cumbersome 92. So its a good compromise.One small question in the back of my mind is that with the advances in LCD screens particularly in cellphones why isn't possible to give this utility a better screen? If a device can be built which relays phone and text messages, has a 2mp camera, can stream video, has an MP3 player on it, and a backlit color screen capable of video playback, all in a space volumetrically equivalent to my wallet it seems like the 89, computing power and all, could be built significantly smaller and with a much nicer display. I realize that the market for graphing utilities is no where near as competitive nor as profit tempting to justify enormous outlays in r/d for enhancements, but you would think some of the technology could be licensed by TI for use in their future utilities. In a world of $200 textbooks an additional $50 or so for a tool like this is pretty insignificant. It's not too hard to imagine this thing having at least a backlit LCD, finer resolution (the 3d graphs are borderline useless), and a rechargeable battery.As futuristic as this utility is compared to earlier ones, a quick comparison with my cell phone or my iPod, already nearly 3yr old, and the contrast looks like technology from two different century's. Well, I suppose they are in fact...The utility, like all other TI, utilities is surprisingly well-built--the durability of these is a credit to TI, who with a market consisting entirely of lucrative bulk school contracts and parents supply-shopping for often careless students, could like textbooks publishers make them as cheaply as possible. I've only seen one of these 89 broken and it was only part of the screen: they are made impressively tough.This rant of mine notwithstanding, as graphing utilities go the 89 is great; although I haven't used the Hewlett-Packards, I can say that the 89 is the standard I've encountered for all undergrad math and science courses. If you're intending to take advances courses in any of the latter you will probably have to buy one of these eventually; accepting the inevitable early you might as well become familiar with it as soon as possible.

As the title, the Titanium is the only major calculator still in production that can calculate complex trigonometry and hyperbolic functions out of the box, while also running on AAA batteries encased in a SCREWLESS lid; the latter being a very important point for being extremely convenient for usage (Li-Ion packs cannot be readily bought on a passerby convenience store in many countries, unlike the older AAA's).While having no color might means it's harder to read graphs, at the very least the absence of backlights is actually not too bad as you can't use calculators in the darkness if the buttons aren't lit either, which none of its rival models could do anyway.And lastly, you can guarantee its admittedly slower CAS to be never hampered by those despicable "exam modes" or a similar sort, unlike the newer flagship models like Nspire or Prime. So better for more serious engineers who'd like emergency CAS machines always on hand if your smartphone connection to Wolfram Alpha shuds down...