Texas Instruments
Back in the 1970's, you were either a TI person or an HP person. The two camps had irreconcilable differences, constantly eager to prove the superiority of their chosen brand of calculators. TI calculators, of course, had a major advantage: they were a lot cheaper. Which is probably one reason why they were more readily available in my native Hungary.
I admit: at the time I also preferred the "AOS" data entry method (algebraic entry with operator precedence) of TI calculators over HP's RPN. Today, I am no longer sure: RPN, once you get used to it, is a lot more efficient, especially when it comes to calculator programming.
Back in the late 70s, however, it was a TI-59 that I was dreaming about. Today, I have several; sadly, except for "New Old Stock" machines, their card readers have either failed or are about to do so, and they're a lot more difficult to repair than the card readers of HP calculators. Yet another point in favor of HP technology!
Keystroke Programmables
Like Hewlett-Packard's, Texas Instruments' first "electronic slide rules" were non-programmable machines, including the SR-50/SR-51 line of products, effective rivals to HP's HP-35 and HP-45. Shortly after the legendary HP-65, however, TI also introduced its first programmables: the SR-56, and the high-end SR-52, a calculator with magnetic cards and an I/O connector for an external printer unit. And now the race was on: for many years afterwards, TI and HP were leapfrogging each other with ever more impressive technological achievements.
Electronic Slide Rules
Texas Instruments was one of several early manufacturers who called their scientific calculators electronic "slide rules". The distinction was important. To an engineer of the 1960s, a calculator (mechanical or electrical) meant a digital device performing the four basic arithmetic functions; the values of transcendental functions were usually computed using printed tables or slide rules. High-end electronic calculators in the 1970s opened up a new frontier: portable calculating devices that went beyond the four arithmetic functions, and packed ever more of the functionality of the engineer's slide rule into a pocket-sized package.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | SR-52 | Scientific | 10+2 LED digits | Partially merged keystroke (224 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 60(22) numbers | Trigonometrics, Exponentials, Magnetic cards |
 | SR-56 | Scientific | 10+2 LED digits | Partially merged keystroke (100 program steps) | Conditionals, Branching, Subroutines | 10 numbers | Trigonometrics, Exponentials |
The Ultimate LED Series
The second generation of TI calculators featured a machine that can easily be called the ultimate LED programmable calculator: the TI-59. This machine's prodigious amount of memory, magnetic card, solid state software modules, and printer interface made it a true marvel of its time.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | TI-57 | Scientific | 8+2 LED digits | Fully-merged keystroke entry (50 program steps) | Conditionals, Branching, Subroutines, Labels | 8 numbers | Trigonometrics, Exponentials, Standard deviation |
 | TI-58 | Scientific | 10(8+2) LED digits | Partially merged keystroke (480 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 60(0) numbers | Trigonometrics, Exponentials, Linear regression |
 | TI-58C | Scientific | 10(8+2) LED digits | Partially merged keystroke (480 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 60(0) numbers | Trigonometrics, Exponentials, Linear regression, Continuous memory |
 | TI-59 | Scientific | 10(8+2) LED digits | Partially merged keystroke (960 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 100(0) numbers | Trigonometrics, Exponentials, Linear regression, Magnetic cards |
Low-end LED Programmables
Before the era of LED calculators has drawn to a close, we saw the birth of a new concept in programmable scientific calculators: that of a low-end machine, cheap in construction, with minimal programming capabilities.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | MBA | Financial | 10(8+2) LED digits | Keystroke entry (32 program steps) | 12(8) numbers | Exponentials, Linear regression, Financial | |
 | TI-42 MBA | Financial | 10(8+2) LED digits | Keystroke entry (32 program steps) | 10(8) numbers | Exponentials, Linear regression, Financial | |
 | TI-51-III | Scientific | 8+2 LED digits | Partially merged keystroke (32 program steps) | 10(8) numbers | Trigonometrics, Exponentials, Linear regression | |
 | TI-55 | Scientific | 8+2 LED digits | Partially merged keystroke (32 program steps) | 10(8) numbers | Trigonometrics, Exponentials, Linear regression |
TI-55 LCD Family
Among the first Texas Instruments programmable calculators with a liquid crystal display was a series of machines that built upon the earlier success of the TI-55 and the MBA. These machines were characterized by a clean keyboard layout and a very simple programming model, capable of storing only a few dozen program steps.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | BA-54 | Financial | 8(5+2) LCD digits | Keystroke entry (40 program steps) | 5(0) numbers | Exponentials, Financial, Continuous memory | |
 | BA-55 | Financial | 8(5+2) LCD digits | Keystroke entry (40 program steps) | 5(0) numbers | Exponentials, Financial, Continuous memory | |
 | TI-53 | Scientific | 8(5+2) LCD digits | Keystroke entry (32 program steps) | 1 numbers | Trigonometrics, Exponentials, Continuous memory | |
 | TI-55-II | Scientific | 8+2 LCD digits | Partially merged keystroke (56 program steps) | 8(1) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Continuous memory, Unit conversions | |
 | TI-55-III | Scientific | 8+2 LCD digits | Partially merged keystroke (56 program steps) | 8(1) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Continuous memory, Unit conversions | |
 | TI-56 | Scientific | 8+2 LCD digits | Partially merged keystroke (56 program steps) | 8(1) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Integration, Continuous memory, Unit conversions |
LCD Programmables
Other early LCD programmables offerred an increased amount of memory, but surprisingly (with the exception of the successors to the TI-57) the programming model remained primitive.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | TI-57 LCD | Scientific | 8+2 LCD digits | Fully-merged keystroke entry (48 program steps) | Conditionals, Branching, Subroutines, Labels | 7(1) numbers | Trigonometrics, Exponentials, Continuous memory |
 | TI-57 LCD Constant Memory | Scientific | 8+2 LCD digits | Fully-merged keystroke entry (48 program steps) | Conditionals, Branching, Subroutines, Labels | 7(1) numbers | Trigonometrics, Exponentials, Continuous memory |
 | TI-57 II | Scientific | 8+2 LCD digits | Fully-merged keystroke entry (48 program steps) | Conditionals, Branching, Subroutines, Labels | 7(1) numbers | Trigonometrics, Exponentials, Continuous memory |
 | TI-60 | Scientific | 10(7+2) LCD digits | Keystroke entry (84 program steps) | 12(1) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Integration, Continuous memory, baseN, Unit conversions | |
 | TI-60X | Scientific | 12 LCD characters | Formula programming (96 program steps) | 12(0) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Fractions, Complex, Continuous memory, baseN, Unit conversions | |
 | TI-68 | Scientific | 12 LCD characters | Formula programming (440 program steps) | 55(0) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Complex, Continuous memory, baseN, Unit conversions, Constants |
"Galaxy" series
The "Galaxy" series represented a change in both appearance and design. Externally, they were characterized by a horizontal layout; internally, these machines were no longer TI-designed, for instance the chipset of the TI-66 was made by Toshiba.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | TI-62 Galaxy | Scientific | 10+2 LCD digits | Fully-merged keystroke entry (100 program steps) | Conditionals, Branching, Subroutines, Labels | 10(1) numbers | Trigonometrics, Exponentials, Linear regression, Continuous memory |
| No Image Available | TI-64 | N/A | |||||
 | TI-65 | Scientific | 10+2 LCD digits | Fully-merged keystroke entry (100 program steps) | Conditionals, Branching, Subroutines, Labels | 16(1) numbers | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Integration, Complex, Continuous memory, Real-time clock, baseN, Unit conversions, Constants |
 | TI-66 | Scientific | 10(8+2) LCD digits | Partially merged keystroke (512 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 64(0) numbers | Trigonometrics, Exponentials, Linear regression, Continuous memory |
 | TI-67 Galaxy | Scientific | 12 LCD characters | Formula programming (1536 bytes) | Conditionals, Branching, Subroutines, Labels | 1536(0) bytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Fractions, Complex, Continuous memory, Constants |
High-end Programmables
At the highest end of TI's keyboard programmable product line are two notable machines: the TI-88 is a legendary unreleased model, whereas the TI-95, despite having the appearance of a BASIC programmable pocket computer, is in fact another high-end keystroke programmable.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | TI-88 | Scientific | 16 LCD characters | Keystroke entry (960 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 120(0) numbers | Trigonometrics, Exponentials, Linear regression, Continuous memory, Real-time clock, Sound |
 | TI-95 | Scientific | 16 LCD characters | Keystroke entry (1000 program steps) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 250(0) numbers | Trigonometrics, Exponentials, Linear regression, Continuous memory, baseN |
Handheld Computers
Like other manufacturers, Texas Instruments also made a few handheld computers; in TI's case, all were programmable in the BASIC language.
BASIC Programmables
Before the era of LED calculators has drawn to a close, we saw the birth of a new concept in programmable scientific calculators: that of a low-end machine, cheap in construction, with minimal programming capabilities.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | CC-40 | BASIC Programmable | 31 LCD characters | BASIC (8 kilobytes) | Conditionals, Branching, Subroutines, Indirect addressing | 8(0) kilobytes | Trigonometrics, Exponentials, Continuous memory |
 | TI-74 | Scientific | 31 LCD characters | BASIC (8 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 8(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Continuous memory |
 | TI-74S | Scientific | 31 LCD characters | BASIC (8 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 8(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Continuous memory |
Graphing Calculators
Presently, Texas Instruments is most famous for its highly successful line of educational graphing calculators, which became the de facto standard in many classrooms in North America and elsewhere. The high-end models, in particular the TI-89, give even Hewlett-Packard a run for their money, matching HP's top-of-the-line models in both features and quality.
Graphing Calculators
TI offers a variety of graphing calculators for all students from high school to college.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
 | TI-73 | Graphing | 96×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 28(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Fractions, Continuous memory, Matrix, baseN |
 | TI-80 | Graphing | 64×48 LCD pixels | Formula programming (7 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 7(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Continuous memory, Matrix, baseN |
 | TI-81 | Graphing | 96×64 LCD pixels | Formula programming (2400 bytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 2400(0) bytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Continuous memory, Matrix, baseN |
 | TI-82 | Graphing | 96×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 28(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Continuous memory, Matrix, baseN |
 | TI-83 | Graphing | 96×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 28(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Matrix, baseN |
 | TI-83 Plus | Graphing | 96×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 28(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Matrix, baseN |
 | TI-83 Plus SE | Graphing | 96×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 24(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Matrix, baseN |
 | TI-85 | Graphing | 128×64 LCD pixels | Formula programming (28 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 28(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Matrix, baseN, Unit conversions, Constants |
 | TI-86 | Graphing | 128×64 LCD pixels | Formula programming (96 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 96(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Complex, Continuous memory, Matrix, baseN, Unit conversions, Constants |
Advanced Graphing Calculators
TI's advanced graphing calculators feature a 16-bit processor, high resolution display, a powerful programming language capable of symbolic manipulation, Flash programmability, and a considerable amount of memory.
| - | Model | Type | Display | Programming model | Programming features | Memory | Special functions |
| Unconfirmed sighting | TI-84 Plus | Graphing | LCD pixels | Conditionals, Branching, Subroutines, Labels, Indirect addressing | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Continuous memory, Matrix, baseN | ||
 | TI-84 Plus SE | Graphing | LCD pixels | Conditionals, Branching, Subroutines, Labels, Indirect addressing | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Continuous memory, Matrix, baseN | ||
 | TI-89 | Graphing | 160×100 LCD pixels | Formula programming (192 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 192(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Matrix |
| No Image Available | TI-89 Titanium | Graphing | LCD pixels | Conditionals, Branching, Subroutines, Labels, Indirect addressing | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Symbolics, Continuous memory, Matrix, baseN | ||
 | TI-92 | Graphing | 240×120 LCD pixels | Formula programming (64 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 64(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Matrix |
 | TI-92 Plus | Graphing | 240×120 LCD pixels | Formula programming (192 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 192(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Matrix |
| No Image Available | TI-92 II | Graphing | 240×120 LCD pixels | Formula programming ( kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Matrix |
 | nspire | N/A | LCD | ||||
 | nspire CAS | Graphing | 320×240 LCD pixels | (16 megabytes) | Trigonometrics, Exponentials, Graphing, Symbolics | ||
 | nspire CX | N/A | CLCD | ||||
 | Voyage 200 | Graphing | 240×120 LCD pixels | Formula programming (192 kilobytes) | Conditionals, Branching, Subroutines, Labels, Indirect addressing | 192(0) kilobytes | Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Matrix |
Other Models
Texas Instruments models that were not yet added to any of the categories listed so far (if any) are shown below.
Variants/OEM Versions
Several Texas Instruments calculators were sold under the Tandy/Radio Shack store brand name.
