... I have owned top of the line graphing and scientific calculators from TI, HP, Casio, Sharp, etc. Back when I was a student, TI's were very cheaply made and often broke quite easily. This machine, the TI-89, Titanium, is definitely not cheaply made and is definitely put together very well. It is also a good improvement over its predecessor, the TI-89 with more memory and with an improved keyboard and improved keyboard "feel" and a much better feature set, etc. The pros and cons as I see it are:

PROS:

1) It has all the standard and CAS (Computer Algebra SYstem) features that we have come to expect on such a machine, plus many nice very detailed and topic as well as course specific APPS that are already preloaded or can be added in electronically and quite simply from the TI website. The interface with a computer is fast and easy to set up.

2) It has a very nice calendar and note storage system for keeping track of coursework and daily workload assignments.

3) It is quite fast with a nice graphical interface and resultant plotting system. The resultant plots are high quality and with the many added features available for enhancement are very intuitive for the learning process.

4) The icon system for choosing where you want to be on the machine can also be converted to a much easier and quicker to navigate text-list system.

5) It has a nice and quite modern, curved body design that sits very nicely both on a desk or a table as well as in your hand.

6) It has a large amount of onboard main memory, plus additional Flash memory for tackling quite memory intensive problems.

CONS:

1) There is no SD card slot as on the HP50g.

2) Integrals are completed by a table look-up process and not by direct manipulation so very little insight can be found by students as to why the result appears the way it does. On the HP50g, in step by step mode, much insight can be gained by the manner in which the integrals are performed for example.

3) The algebraic operating system is the only choice available on this machine which usually requires many more keystrokes to do a complicated problem.

4) The available programming languages are quite limited on this machine as compared again to the HP50g.

5) Some functions that you would readily expect to be available with a single key press require instead at least two key presses, but usually with only a single shift key press first.

6) The color coding choices are not nearly as distinctive and easy to quickly recognize as on the HP50g.

7) As with the HP50g, it require multiple batteries plus a backup coin cell battery to save everything briefly when changing the main batteries.

8) TI should also impliment a fine backlight system for viewing the screen at low light levels, as recently included on the Casio FX-9860g Slim version for example. ...
Check Amazon Price and Read More Reviews on Texas Instruments TI-89 Titanium Graphing Calculator

... It can do almost anything, including the ability to play games on it (I have played SF2 on it, wow), it can resolve equations of almost all kind, but the manual is terrible and I haven't found a way to make programs on it ...
Check Amazon Price and Read More Reviews on HP 50g Graphing Calculator (F2229AA#ABA)

... I've been using these at work for years, and everybody keeps stealing them from me because they are great. They're great desk calculators with big numbers for quick, easy, and accurate entry and a -/+ key for entering negative numbers. Can't believe I'm writing a review for a calculator, but I really LOVE these. ...
Check Amazon Price and Read More Reviews on Texas Instruments TI1795SV Solar Calculator

... This is an excellent choice for those that have to work with computers. I examined lots of calculators. I even bought an HP33 and a TI model as well. What I need most is logic operations and number system conversions. AND NOT OR NOR XOR, etc. Plus I need Hexadeciman and binary number systems. Lots of calculators offer these features, but they are buried in multiple key combinations and special modes. This calculator has the logic operations written on the keys. This is good because 6 months later you will not recall any special instructions so if its not intuitive and its not readily available, you will be going back to the instructions. So having these operations listed on the keys was an absolute must for me. It also has the number system conversions listed so I can convert from decimal to hex and binary easily too. The one thing that could be better is entry of numbers in different systems. It will not really add numbers from different systems together. If you want to add two numbers, you will have to convert them to the same system first. Its easy to do, but it just adds some steps no needed by say the HP33. But of course the HP33 requires more steps for other more important things, so this calc still gets the nod. Not to mention its far superior price. And its also got Pent number system which I assume is base-5. Nice touch though I can't imagine anyone require this.

I like the write view though I am still getting used to editing it. I like the fraction display. I like the Fixed/Scientific/Engineering notations. I keep mine on engineering with TAB 9.

I'm sure it does other things, but I will let other people comment on those things. I'll just say that its an excellent calculator for a computer programmer / designer.

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Check Amazon Price and Read More Reviews on Sharp EL-W516B Scientific Calculator with WriteView (Black)

... I was looking to replace a very old ten-key adding machine with a calculator with enough digits to display the large numbers I work with. I could find 8 or 9 digits, but I needed something much larger. I found this Casio Printing Calculator with 12-digit display at a very reasonable price. Thank you. ...
Check Amazon Price and Read More Reviews on Casio HR-100TM 2-Color Printing Calculator

... The calculator was in perfect condition actually it was brand new and it was half the price. I'm happy... ...
Check Amazon Price and Read More Reviews on HP 10bII Financial Calculator

... I use this calculator in all of my math and science classes and it works great! I also plan to use this for college, so it is a great investment for any high school or college student. Have had no problems at all with it. I highly recommend this calculator. ...
Check Amazon Price and Read More Reviews on Texas Instruments TI-84 Plus Silver Edition Graphing Calculator