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TI CALCULATOR HISTORY
1972-1980

Last Update: January 26, 2004 -- THE TI REFERENCE


New Models added: TI-15 (German), TI-31, TI-33, TI-41, TI-42 MBA, TI-45, and the TI-2550-IV. Thanks to Thomas Brockmeier.

Lots of Info on the Scientific models from Gene Wright.


  SR-10 - 1st
    FUNCTIONS:	Four w/Exponent, square root, square, reciprocal
    MEMORIES:	None
    DISPLAY:	12 LEDs
    KEYBOARD:   23 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  3-AA NiCads (internal)
    PHYSICAL:	6.3" x 3.1" x 1.5"
    WEIGHT:	10 ounces
    PRODUCTION:	1972
    COST:	$149.95
    INFO:	o The "SR-10" logo is situated in the escutcheon 
		  surrounding the display.
		o TI's first "SR" (Slide Rule) model.
		o This was a big hefty unit. Hardly hand-held.

* SR-10 - 2nd
    FUNCTIONS:	Four w/Exponent, square root, square, reciprocal
    MEMORIES:	None
    DISPLAY:	12 LEDs
    KEYBOARD:   23 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  3-AA NiCads (internal)
    PHYSICAL:	6.3" x 3.1" x 1.5"
    WEIGHT:	10 ounces
    PRODUCTION:	1973
    COST:	$89.99
    INFO:	o The "SR-10" logo is situated in the upper area of 
		  the faceplate.

* SR-11
    FUNCTIONS:	Four w/Exponent, square root, square, reciprocal and pi
    MEMORIES:	None
    DISPLAY:	12 LEDs
    KEYBOARD:   24 buttons
    SWITCHES:   Top Right On/Off
                Top Right keyboard Constant
    BATTERIES:  3-AA NiCads (internal)
    PHYSICAL:	6.3" x 3.1" x 1.5"
    WEIGHT:	9 ounces
    PRODUCTION:	Announced September 11, 1973
    COST:	$119.95 intitially, $79.95 later
    INFO:	o The Sr-11 was like the SR-10, but with pi and a constant.
		o Much less hefty than the SR-10.

  TI-15
    FUNCTIONS:	Four plus 1/X, X*X, Square Root of X, Pi
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	~9 volt
    PHYSICAL:	~5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	German model
    INFO:	o Info from Thomas Brockmeier

  SR-16
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	12 LEDs
    KEYBOARD:   31 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  
    PHYSICAL:	6.3" x 3.1" x 1.5"
    WEIGHT:	8.3 ounces
    PRODUCTION:	Introduced on October 25, 1974
    COST:	$99.95
    INFO:	o The SR-16 was a Scientific calculator.
		o Superseded by the SR-16II within a year.

* SR-16 II
    FUNCTIONS:	Scientific:
		x^2, sqrt(x), 1/x, y^x, e^x, LNx, Log, One memory 
		register with store, recall, and sum.
    MEMORIES:	1
    DISPLAY:	12 LEDs
    KEYBOARD:   31 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  3-AA NiCads
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	8.25 ounces
    PRODUCTION:	Introduced on August 1, 1975
    COST:	$49.95
    INFO:	o Possibly the last TI slide rule calculator that did 
		not have trig functions.

  SR-20
    AC only version of the SR-22
    SR-20 was a slightly advanced desktop calculator.  
    It had an x! key.  

  SR-22
    FUNCTIONS:	Four plus octal, decimal and hexadecimal conversion
    MEMORIES:	
    DISPLAY:	12 neon gas discharge display (10 + 2)
    KEYBOARD:	34 buttons
    SWITCHES:   Right Side On/Off
		Left-Center of Keyboard AUTO/MAN Base Change
    BATTERIES:  
    PHYSICAL:	9.0" x 6.5" x 2.75"
    WEIGHT:	
    PRODUCTION:	Announced on September 11, 1973
    COST:	$350 plus $50 for the battery pack
    INFO:	o The SR-22 hexadecimal calculator, It converts between 
                  octal, decimal and hexadecimal.  
		o There are 3 LEDs in the keypad area which light to 
		  indicate which base you are working in. 
		o A very unique feature is that these conversions are 
		  performed on floating-point numbers, not integers. 
                o For example decimal 2.5 converts to 2.8 in hexadecimal 
		  and 2.4 in octal. (from Mike Sebastian)
        o The conversions are very slow, like several seconds.
        o Its color scheme was much like that of the SR-11, with
          white, grey, blue, and orange keys.
        o The ad text reads:
            model SR-20 desk calculator with 14-character display has eight special
            function keys--pi, epsilon, exponent, factorial. integral [integer portion
            of x], square root, squaring, reciprocal, [$]179.95.

            The key layout in the photo are

            INT x   pi      e       EE      CD      C

            x^2     7       8       9       x       / [divide]
            \/x     4       5       6       +       -
            x!      1       2       3       +       -
            1/x     0       .       +/-     =       =

            +, -, and = are double-size keys.  
            CD, C, and 1-9 are white; = is orange.
            Keys on left and remainder on top row are blue.  
            All other keys are grey.
                from Jeff Woolsey 

  TI 25
    Functions: Scientific
    Memories: 1
    Display: 9 LCDs (8 + 1 or 5 + 2 + 2)
    Keybord: 40 buttons
    Switches: None (Key 4 = OFF, Key 5 = ON/C)
    Batteries: 2 Silveroxid (3 V)
    Pysical: 5.2" x 3.0" x 0.4"
    Weight: 80 g
    Production: 1978
    cost: 75 DM in Germany
    INFO: can almost the same as the TI 30, but has no hyperbolic
        functions, therefore 1 dim statistic
	totally black body
	fixed in a map like the typical Japanese calculator 

* TI-30
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	5.25 ounces
    PRODUCTION:	1976
    COST:	$24.95
    INFO:	o The best selling calculator ever.

  TI-31
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	~9 volt
    PHYSICAL:	~5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	
    INFO:	o Info from Thomas Brockmeier

  TI-33
    FUNCTIONS:	Scientific
    MEMORIES:	3 (thanks Andre from Wuppertal, Germany)
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	~9 volt
    PHYSICAL:	~5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	
    INFO:	o Info from Thomas Brockmeier

  TI-38
    Constant Memory (in beautiful black, I remember there was
    another color, maybe silver) was made in Italy, the number is 4179 PCI,
    so perhaps the correct year might be 1979.
    from Achim (alewand@forwiss.uni-erlangen.de) 

* SR-40
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	2-AA NiCads to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	5.74 ounces
    PRODUCTION:	1976
    AVAILABLE:	Easy
    INFO:

  TI-41
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	2-AA NiCads to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	
    INFO:	o Info from Thomas Brockmeier

  TI-42 MBA
    FUNCTIONS:	Scientific/Business
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off 
    BATTERIES:	~2-AA NiCads to 9 volt
    PHYSICAL:	~5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	
    INFO:	o Info from Thomas Brockmeier

  TI-45
    FUNCTIONS:	Scientific
    MEMORIES:	1
    DISPLAY:	9-digit fluorescent blue-green display (not ~12 LEDs)
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:	~2-AA NiCads to 9 volt
    PHYSICAL:	~5.8" x 3.2" x 1.4"
    WEIGHT:	~5.74 ounces
    PRODUCTION:	1978
    AVAILABLE:	
    INFO:	o Info from Thomas Brockmeier
            o Jan Kronlund from Finland has a TI-45 with a blue 
                electrolumicent display
              Jens-Eike Hartwig (j-e_hartwig@t-online.de) used a 
               TI-45 in 1978 (at school, 8th grade). 
              Has a 9-digit fluorescent green display (8 digits + sign/DRG-symbols)
            o Per Hilton from Asker, Norway            
                Display is not LED, but VFD (Vacuum Fluorescent), 9 digits.
                Same functions as TI-30, but no power-saving "walking dot" mode 
                  (just turns off after around 7 minutes).
                Chip is TMC1983NL, display Itron FG95B1.
                Power consumption (9V) is 25uA when off, 14-15mA when on
                  (vs. 40-60mA for TI-30).

* SR-50
    FUNCTIONS:	Scientific:
		x^2, sqrt(x), 1/x, %, y^x, x root y, factorial, trig,
		hyperbolic trig functions, e^x, LNx, Log, Degrees to 
		Radian conversion and vice versa, degree/radians switch, 
		One memory register with store, recall, and sum.
    MEMORIES:	1
    DISPLAY:	14 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
                Top Left Radians/Degrees
    BATTERIES:  3-AA NiCads
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	
    PRODUCTION:	Announced on January 15, 1974
    COST:	$169.95
    INFO:	o The first SR-50 was first marketed by direct mail.
		o Like the SR-11, this machine has brightly colored blue, 
		  orange, and gray keys, along with white for digit entry. 
		o Also has a silver area that comes down below the first 
		  row of keys. 
		o It also marks the start of Texas Instruments assault on
		  the HP slide rule calculators.

* SR-50A
    FUNCTIONS:	Scientific: Same as the SR-50
    MEMORIES:	1
    DISPLAY:	14 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:	3-AA NiCads
    PHYSICAL:	6.0" x 3.2" x 1.3"
    WEIGHT:	8.25 ounces
    PRODUCTION:	1975
    COST:	$109.50
    INFO:	o This model was introduced to standardize this model with
		  the SR-52, SR-56, SR-51A to reduce costs. 
		o It also has a more business-like case/key color scheme.
		o Kind of bland compared to the SR-50. 
		o This machine possibly works with the PC-100 series 
		  printers.
        o TI-50 Simline LCD serise replaced this popular LED version

* SR-51
    FUNCTIONS:	Scientific and Financial:
		x^2, sqrt(x), 1/x, y^x, x root y, factorial, permutations, 
		mean, variance, std deviation, Linear regression with 
		trend line projection, random number generator, trig, 
		hyperbolic trig functions, e^x, LNx, Log, 10^x, %, 
		% change, 20 different conversions, degree/radians switch, 
		Three memory registers with full register arithmetic.
    MEMORIES:	3
    DISPLAY:	14 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
                Top Left Radians/Degrees
    BATTERIES:	3-AA NiCads
    PHYSICAL:	6.0" x 3.2" x 1.3"
    WEIGHT:	8.25 ounces
    PRODUCTION:	Introduced about March of 1975
    COST:	$224.95
    INFO:	o TI replaced the SR-50 and SR-51 in mid-1975 with 
		  the "A" models.
		o The SR-51 had been marketed only a few months when 
		  this happened, so it's quite rare.  
		o This calculator is also more stylish than any of 
		  TI's other advanced models.
		o First machine to offer permutations and a built-in 
		  random number generator. 
		o First TI to allow FIX decimal point?
		o This machine also had bright colors like the SR-50.

  SR-51A
    FUNCTIONS:	Scientific and Financial
    MEMORIES:	3
    DISPLAY:	14 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
                Top Left Radians/Degrees
    BATTERIES:	3-AA NiCads
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	8.3 ounces
    PRODUCTION:	Introduced about March of 1975
    COST:	$224.95
    INFO:	o This model was introduced to standardize this model 
		  with the SR-52, SR-56, SR-50A to reduce costs. 
		o It also has a more business-like case/key color scheme.
		o Kind of bland compared to the SR-51.  
		o This machine possibly works with the PC-100 series 
		  printers.

* SR-51-II
    FUNCTIONS:	Scientific and Financial
    MEMORIES:	3
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:	2-AA NiCads to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	7.5 ounces
    PRODUCTION:	1976
    COST:	$80.00
    INFO:

* TI-51-III
    FUNCTIONS:	Scientific and Financial and Programmable
    MEMORIES:	10
    PRGM STEPS: 32 (and 8 Memories) or 24 (9) or 16 (8)
    DISPLAY:	12 LEDs (8+2+2)
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  2-AA NiCads to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.25 ounces
    PRODUCTION:	1976
    COST:	$80.00
    INFO:	o Programmable
            o Successor of the SR 51 II
            o Same body as TI 57
            o 2 dim statistic with keys for correlation, slope, zero-point, x and y
            o Value convert inch to mm, gal to l, lb to kg, įF to įC
            o Only rudimentary programmable, therefore programmable functions (R/S,
              Rst, Lrn, Sst) covers 2nd keys and branches, pause or even backstep
              doesnít exist.
        
        from Albert Rupprecht  

        I bought a TI 51 III in spring 1980 because at the age of 13 I didnít
        no the difference to the TI 57. So I thought with more 2nd function
        keys itís the better calculator. TI 51 III and TI 57 had the same
        body, therefore I suppose both were introduced at the same time and
        started with a anodised legend witch later became a plastic relief
        (like my model). The manualís handbook copyright is from 1977 and my
        model looks like the one on your TI 55 photo - so the TI 55 possible
        called TI 51 III in Germany (by the way: I canít remember a TI 55). I
        would talk about a scientific and statistic calculator because it
        hasnít got any financial functions! Unlike the TI 57 it doesnít carry
        the letters ĒProgrammableĒ because it hasnít got X=T, X>=T, Label, SBR
        or even BST! For having a Pause the manuel suggests using 10 times Ē=Ē
        then you can see the result flickering!
        But - that must be said - it calculated well, much better as the TI 55
        II from 1982 I bought next. This model was so worse that I though it
        away at last! First I discover a disastrous round mistake (by convert
        DMS to DD) and then using the keys was impossible - the display show
        either nothing or too much of the same numbers - like so many TI
        calculators of this time.
        About the other calculators I donít know much, but the TI 57 had 50
        (not 150) steps and the TI 58 480 and no memories or 8 less per
        memory! Also the TI 59 (960 - 100 to 120 - 0). You shout mentioned
        that the magnetic card reader was integrated and - this was very
        clever and useful - the cardís backside could be used as labels for
        the softkeys A to E!. 
        Surly also worth to mention: The TI 30 wrote ĒErrorĒ with its display.
        And the 3 to 9 V battery pack didnít offer a overcharge-protection, so
        the user could destroy the pills very easily.
        And TI sold the models TI 25 and TI 53 in Germany - they had perhaps
        another name in the USA! These LCD-models existed already in early
        1979, so they might came out in autumn 1978:

* SR-52
    FUNCTIONS:	Scientific and Programmable:
		224 program steps, Card reader, 20 memories (see below), 
		full log, trig, and algebraic functions. Program steps 
		are completely unmerged. To store a number into memory 1 
		requires 3 steps. STO, 0, 1. 
    MEMORIES:	20
    PRGM STEPS: 224
    STORAGE:	2 7/8-inch by 5/8-inch magnetic cards
    DISPLAY:	14 LEDs
    KEYBOARD:   45 buttons
    SWITCHES:   Top Right On/Off
		Top Left Redians/Degrees
    BATTERIES:  
    PHYSICAL:	
    WEIGHT:	12.3 ounces
    PRODUCTION:	Introduced September 16, 1975
    COST:	$395
    INFO:	o The SR-52 was an early and popular programmable 
		  scientific calculator.  
		o An optional printer, the PC-100, was introduced 
		  January 7, 1976.
		o First TI programmable, First programmable to offer 
		  Indirect addressing (Which I think was a big 
		  milestone), and to branch on an error?, 
                  first TI with AOS and parentheses, 
		o Thickest TI ever made. 
		o Sure uses the INV key a lot.
		o This machine had a few goodies built-in to it that 
		  many people did not know about. 
			--Memories 98 and 99 were full memories in 
			  addition to the 00-19 memories. 
			--Also, storing into memory locations 70 and 
			  above stored into program memory. 
			--Storing into memories 60-69 affects pending 
			  operations stack. You could get a total of 
			  over 50 memories on this machine. 
		o Case design is similar to the SR-50A, 51A, and 56.

TI 53
    FUNCTIONS: Scientific and Programmable
    MEMORIES: 1 (Iím not sure!!!)
    PRGM STEPS: 32 
    DISPLAY: 9 LCDs (8 + 1 or 5 + 2 + 2)
    KEYBOARD: 40 buttons
    SWITCHES: None (Key 4 = OFF, Key 5 = ON/C)
    BATTERIES: 2 Silveroxid (3 V)
    PHYSICAL: 5.2" x 3.0" x 0.4"
    WEIGHT: I suppose 80 g
    PRODUCTION: 1978
    COST: ?
    INFO: Constant Memory, same body as TI 25 but in silver
          no statistic functions
          only rudimentary programmable, programmable keys 
          are R/S, Rst, Lrn, SST fixed in a map

  TI-54
    Exists -- Need info  

* TI-55
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	10
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:	2-AA NiCad to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.5 ounces
    PRODUCTION:	1977
    COST:	
    INFO:	o Budget scientific model.

  TI-55II
    scientific slimline w/angled LCD display
    
  SR-56
    FUNCTIONS:	Scientific:
		Full log, trig, and algebraic functions. 
    MEMORIES:	10
    PRGM STEPS: 100
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
		Top Left Gradent/Degrees
    BATTERIES:  
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	8.3 ounces
    PRODUCTION:	Announced on January 21, 1976
    COST:	$179.95
    INFO:	o Works with PC-100 and 100A printer.
		o First TI key programmable.
		o First TI since the SR-50 not to include factorial. 
		o First TI to include a Pause function. 
		o First programmable to use an independent test 
		  register for branching?
		
  SR-56 Programmable
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	10
    PRGM STEPS: 100
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
		Top Left Gradent/Radians/Degrees
    BATTERIES:  
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	8.3 ounces
    PRODUCTION:	
    COST:	$139.00
    INFO:

* TI-57 type 1
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	8
    PRGM STEPS:	150, Key programmable
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  2-AA NiCad to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.5 oz
    PRODUCTION:	Introduced on May 24, 1977
    COST:	$79.95
    INFO:	o The TI-57 superseded the SR-56.
		o TI legend anodized on aluminum.
		o Most people do not know that any TI-57 can be made 
		  into a TI-57C by sacrificing the last two program 
		  steps.  Program memory is retained at little or no 
		  battery drain, but unit is NOT switched off. 
		  How?: At step 48 of your program memory, place the 
		  following: 2nd Exc SST LBL 1.  Press LRN. When you 
		  want to switch your calculator off, press GTO 2nd 
		  48, R/S, INV STO 3 +/- +/-.  The display will go 
		  blank.  It uses even less energy than the TI-58C 
		  to store programs this way.  When you want to 
		  switch the calculator back on, press INV FIX CLR.
		  Try it.

* TI-57 type 2
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	8
    PRGM STEPS:	150, Key programmable
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  2-AA NiCad to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.25 oz
    PRODUCTION:	Introduced on May 24, 1977
    COST:	$79.95
    INFO:	o The TI-57 superseded the SR-56.
		o TI legend in plastic relief

* TI-58
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	60
    PRGM STEPS: 480, Key programmable
    DISPLAY:	12 LEDs
    KEYBOARD:   45 buttons
    SWITCHES:   Top Left On/Off
    BATTERIES:	3-AA NiCads
    PHYSICAL:	6.4" x 3.2" x 1.5"
    WEIGHT:	8.5 ounces
    PRODUCTION:	Introduced on May 24, 1977
    COST:	$124.95
    INFO:	o Replaced with the 58C in 1979
		o One of the last key programmables that lost 
		  program memory when turned off.  This significantly 
		  lowers its value and usefulness.
		o First machine to use ROM cartridges. 
		o This machine has the ability to run programs in 
		  fast mode. Speeds execution by about 25%.

* TI-58C
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	60 or
    PRGM STEPS: 480, Key programmable.
    DISPLAY:	12 LEDs
    KEYBOARD:   45 buttons
    SWITCHES:   Top Left On/Off
    BATTERIES:  
    PHYSICAL:	6.4" x 3.2" x 1.5"
    WEIGHT:	8.5 ounces
    PRODUCTION:	1979
    COST:	
    INFO:	o Model 58 with continuous memory.
		o Works with PC-100A and 100C printer.
		o Corrects the primary deficiency of the TI-58 in 
		  that it remembers memory when turned off!
		o First machine to use ROM cartridges. This machine has 
		  the ability to run programs in fast mode. Speeds 
		  execution by about 25%.

* TI-59
    FUNCTIONS:	Scientific and Programmable
    MEMORIES:	100 or
    PRGM STEPS: 960
    STORAGE:	Magnetic cards
    DISPLAY:	12 LEDs
    KEYBOARD:   45 buttons
    SWITCHES:   Top Left On/Off
    BATTERIES:	2-AA NiCad
    PHYSICAL:	6.4" x 3.2" x 1.5"
    WEIGHT:	10 ounces
    PRODUCTION:	Introduced on May 24, 1977
    COST:	$299.95
    INFO:	o Modules containing programs with up to 5000 steps 
		  were available for this calculator. 
		o A magnetic card reader was available.
		o Surprisingly common, given its expense and 
		  sophistication.  
		o Works with PC-100A and 100C printer.
		o Largest memory capacity of ANY programmable until 
		  HP-41C introduced.
		o First machine to use ROM cartridges. 
		o Card readers on these units are notoriously unreliable. 
		o First machine to use ROM cartridges. 
		o This machine has the ability to run programs in fast
		  mode.  Speeds execution by about 25%.

  SR-60A (Scientific Desktop)
    FUNCTIONS:	Scientific
    MEMORIES:	100
    PRGM STEPS: 480/1920
    DISPLAY:	20 LEDs
    KEYBOARD:   95 keys
    SWITCHES:   
    BATTERIES:  AC power
    PHYSICAL:	Desktop
    WEIGHT:	~26 lbs
    PRODUCTION:	1976
    COST:	1695.00
    INFO:	o Card Reader and Printer built in
		o Desktop card programmable. 
		o Had over 2000 program steps when expanded and 
		  prompted with alpha characters.

  TI-88
	Date Introduced: Never.
	Price: N/A
	Functions:
	Info:	o TI equivalent to the HP-95C!
		o Biggest hyped vapor-calc ever. 
		o This was to be the TI response to the HP-41C.
		o Had alpha, etc.
		o Hyped to many TI-59 owners, but then withdrawn 
		  without comment.
		o Obviously very rare. If you ever find one, buy it.

        from Arthur Hagen  

        Also, I'm one of the lucky few who has actually put my hands on a TI-88.
        It came (or didn't, as it turned out) with two slots in the rear, for
        expansion, and was clearly meant to hit the same market as the HP-41.
        Unfortunately, the TI representative wouldn't let me buy the demo model.

  TI-95 PROCALC.
    FUNCTIONS:	Scientific
    MEMORIES:	8k memory expandable to 16k
    PRGM STEPS: Fully programmable
    DISPLAY:  15 character by 2 line dot matrix display
              Second line in display used as 5 "soft labels"	
    KEYBOARD: 65 keys: 21 math keys
              5 programmable function keys
              9 top menu keys
    SWITCHES:   
    BATTERIES:  
    PHYSICAL: 8" X 3.75" X 1" size
    WEIGHT:	
    PRODUCTION:	Manufactured 1986
    COST:	
    INFO:	o i/o port
            o cartridge port
            o hard shell case
            o available accessories
               : tape interface, 
               : thermal printer, 
               : rom and ram cartridges.
    Notes: based on tms 1000 cpu, used a lot of nested menus for functions.
    programming used an extended version of AOS and even allowed direct
    execution of ml programs routines. 
 
    A similar calculator called the BasicCalc with different roms and
    keyboard was released at about the same time.
    It runs BASIC, holds 8k of memory, a maximum of 16k.  It has 113 instructions.

  TI-150
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	xx Orange Vacuum-fluorescent
    KEYBOARD:	19 buttons
    SWITCHES:   Top Right On/Off
		Top Left Decimal Point Adjust
    BATTERIES:  4-AA
    PHYSICAL:	6.5" x 3.2" x 1.8"
    WEIGHT:	10 ounces
    PRODUCTION:	1974
    COST:	
    INFO:	o Possibly the rarest TI.  
		o The keys and body style of the 2550, painted-on 
		  silver trim of SR-10.
		o No memory or fixed decimal switch as on 2550.  
		o Unusual orange display.

* TI-1000 type I
    FUNCTIONS:	Four, plus percentages
    MEMORIES:   None
    DISPLAY:	8 LEDs
    KEYBOARD:   20 buttons
    SWITCHES:   None
    BATTERIES:  9 volt
    PHYSICAL:	5.4" x 2.9" x 1.3" 
    WEIGHT:	4.5 oz
    PRODUCTION:	1977
    COST:	$9.77
    INFO: 	o Gold trim

* TI-1000 type II
    FUNCTIONS:	Four, plus percentages
    MEMORIES:   None
    DISPLAY:	8 LEDs
    KEYBOARD:   20 buttons
    SWITCHES:   None
    BATTERIES:  9 volt
    PHYSICAL:	5.4" x 2.9" x 1.3" 
    WEIGHT:	4.5 oz
    PRODUCTION:	1977
    COST:	$9.77
    INFO:	o Brown trim

* TI-1025
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	1
    DISPLAY:	8 Vacuum-fluorescent
    KEYBOARD:   24 buttons
    SWITCHES:   None
    BATTERIES:	9 volt
    PHYSICAL:	5.4" x 2.9" x 1.3"
    WEIGHT:	5.25 ounces
    PRODUCTION:	1977
    COST:	$11.77
    INFO:	o Often found with in the origional box.

  TI-1050
    FUNCTIONS:	Four, plus percentage and square root
    MEMORIES:   2 KEY MEMORY
    DISPLAY:	8 Blue Vacuum-fluorescent
    KEYBOARD:	24 buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 3.0"
    WEIGHT:	
    PRODUCTION:	1977
    COST:	$12.95
    INFO:	o Another entry in the 1000/1025 line.
		o Automatic Constant

* TI-1200
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:   19 buttons
    SWITCHES:   Left Side On/Off
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.8" x 1.4"
    WEIGHT:	5.5 oz
    PRODUCTION:	1975
    COST:	$14.88
    INFO:	o Often found in the origional box.
		o The 1200 series styling was used on many other TI 
		  calculators and they all shared the annoying 
		  characteristic of loose or missing faceplates.

  TI-1200 "Lady"
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:	19 buttons
    SWITCHES:   Left Side On/Off
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.8" x 1.4"
    WEIGHT:	5.5 ounces
    PRODUCTION:	1975?
    COST:	
    INFO:	o The 1200 with more "feminine"-colored faceplate and keys.

  TI-1205
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	
    INFO:	o Another colorful 1200 relation, but this one has 
		  oversized lettering too.

  TI-1220 (T-1220)
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	
    INFO:	o This (and the 1225) are somewhat obscure, but 
		  otherwise ordinary, 1200 series units.

  TI-1225 (T-1225)
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	
    INFO:

* TI-1250
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   24 buttons
    SWITCHES:   Left Side On/Off
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.8" x 1.4"
    WEIGHT:	5.5 oz
    PRODUCTION:	Introduced on June 1, 1975
    COST:	$24.95
    INFO:

  TI-1255
    It has a bright blue (darker than the Lady 1200) face plate 
    and an ivory colored case (same as the Lady 1200).  Oddly, the rear label 
    which is black states that it is a TI-1250 but the face plate has TI-1255 on 
    it. from Cleo McCall (ApexMcCall@aol.com )

  TI-1265
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx Blue Vacuum-fluorescent
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.8" x 1.4"
    WEIGHT:	
    PRODUCTION:	Introduced on April 9, 1976
    COST:	
    INFO:	o Has a Blue florescent display, unique within the
		  1200 series.

* TI-1270
    FUNCTIONS:	Four, plus reciprocal, square, square root, and pi
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   24 buttons
    SWITCHES:   24
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.8" x 1.4"
    WEIGHT:	5.5 oz
    PRODUCTION:	Introduced on April 21, 1976
    COST:	$18.95
    INFO:	o The TI-1270 was designed for use in secondary schools.
		  Colorful model.  
		o TI appeared to like orange.

  TI-1400
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	None
    DISPLAY:	xx LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	
    INFO:	o Has a brown carrying case, not the usual black.
		o Similar styling to the 1200.

  TI-1450
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	$16.00
    INFO:

* TI-1500
    FUNCTIONS:	Four, plus percent
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:   19 buttons
    SWITCHES:   Top Middle Left On/Off
    BATTERIES:  2-AA NiCads (internal)
    PHYSICAL:	5.0" x 2.6" x 1.0"
    WEIGHT:	7 ounces
    PRODUCTION:	Introduced April 8, 1974
    COST:	$69.95, later lowered to $59.95
    INFO:	o Nifty little unit with thick chrome borders.

  TI-1600
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	None
    DISPLAY:	8 Blue Vacuum-fluorescent
    KEYBOARD:   20 buttons
    SWITCHES:   
    BATTERIES:  xx NiCad
    PHYSICAL:	5.0" x 3.0"
    WEIGHT:	
    PRODUCTION:	Introduced on June 13, 1976
    COST:	$24.95
    INFO:	o The 1600 series consisted of slimmed-down models that 
		  preconfigured the styling of LCD units.

  TI-1650
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	yes
    DISPLAY:	xx Blue Vacuum-fluorescent
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  xx NiCad
    PHYSICAL:	5.0" x 3.0"
    WEIGHT:	
    PRODUCTION:	Announced June 13, 1976
    COST:	$29.95
    INFO:

  TI-1680
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	1, plus 20 line recall
    DISPLAY:	8 Blue Vacuum-fluorescent
    KEYBOARD:	24 buttons
    SWITCHES:   None
    BATTERIES:  xx NiCad
    PHYSICAL:	5.0" x 3.0"
    WEIGHT:	
    PRODUCTION:	Introduced on June 5, 1977
    COST:	$29.95
    INFO:	o The TI-1680 could re-display up to 20 past numbers 
		  on its display, instead of having a printer.
		o Allowed some primitive editing of those entries.

  TI-1700 - DataClip
    FUNCTIONS:	Four plus percentage
    MEMORIES:	1
    DISPLAY:	8 LCDs
    KEYBOARD:   22 buttons
    SWITCHES:   None
    BATTERIES:  Three Silver Oxide
    PHYSICAL:	About the proportions of a six-inch ruler
    WEIGHT:	
    PRODUCTION:	Announced on June 5, 1977
    COST:	$34.95
    INFO:	o LCD calculator shaped like a 6-inch ruler.  
		o High quality, unlike its many knockoffs.

* TI-1750 (1st LCD)
    FUNCTIONS:	Four, plus square root and percentages
    MEMORIES:	4 key memory
    DISPLAY:	8 LCDs
    KEYBOARD:	24 buttons
    SWITCHES:   Top Left below display On/Off
    BATTERIES:  Two silver oxide 
    PHYSICAL:	4.5" x 2.7" x .4"
    WEIGHT:	less than 2.5 ounces
    PRODUCTION:	Introduced in mid-April of 1977
    COST:	$24.95 
    INFO:	o TI's first LCD calculator.
  
TI-1790 Data Chron
   FUNCTIONS:   Four plus square root and  percentage
   MEMORIES:    One
   DISPLAY:     8 LCDs plus day of week
   KEYBOARD:    25 buttons
   SWITCHES:    Time set , alarm set am,pm start/stop lap/reset,time call ,day ,date, time
   BATTERIES:   2 ea G13
   PHYSICAL:    2 5/8 "x 5 5/8 x 3/8
   WEIGHT:      4.3 oz with case
   PRODUCTION:  Introduced January 5, 1978
   COST:        $50
   INFO:        o The DataChron calculator incorporated a watch with
                  stopwatch and alarm.
  TI-2000
    FUNCTIONS: Four
    MEMORIES: None
    DISPLAY: 7 LEDs (RED)
    SWITCHES: Top left side On/Off
    BATTERIES: 3x AA
    PHYSICAL: 13cm tall, 7cm wide, 3.5cm thick
    PRODUCTION: ~1974
    INFO: The face plate is orange with a black TI-logo in the upper-left
          corener, and silver lettering for the model ("TI-2000" in the
          upper-right corner), and in silver the word "ON" right below 
          the on/off switch which is below the TI-logo.
            from Eric (itdept@altrex.nl)
    The key layout:
        [on/off][C] [/]
        [7] [8] [9] [x]
        [4] [5] [6] [-]
        [1] [2] [3] [+]
        [CE][0] [.] [=]

  TI-2500 Datamath - 1st
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:	18 buttons
    SWITCHES:	Top Left Side On/Off
                Chain/Constant switch
    BATTERIES:	4-AA NiCads (internal)
    PHYSICAL:	5.5" x 3.0" x 1.7",
    WEIGHT:	12 ounces
    PRODUCTION:	Introduced September 21, 1972
    COST:	$119.95
    INFO:	o Four and a half hours battery life were claimed.
		o The TI-2500 was TI's first hand calculator. 
		o It was introduced along with the TI-3000 and 
		  TI-3500 desk-top calculators.
		o This model states a recharging time of 16 hours 
		  on the back plate.
		o Two screws hold the battery compartment hatch on.
        o A LCD version of the Datamath called the Minimath.
          It was a prototype and never released.
          
* 2500 Datamath - 2nd
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:   18 buttons
    SWITCHES:   Top Left Side On/Off
                Chain/Constant switch
    BATTERIES:  4-AA NiCads (internal)
    PHYSICAL:	5.5" x 3.0" x 1.7"
    WEIGHT:	12 ounces
    PRODUCTION:	1973
    COST:	$119.95
    INFO:	o This model states a recharging time of 10 hours on 
		  the back plate.
		o No battery compartment hatch, have to remove entire back.

* TI-2500 Datamath-3rd - same as TI-2500B Datamath
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:   18 buttons
    SWITCHES:   Top Left Side On/Off
                Chain/Constant switch
    BATTERIES:  4-AA or 3-NiCads (internal)
    PHYSICAL:	5.5" x 3.0" x 1.7"
    WEIGHT:	12 ounces
    PRODUCTION:	
    COST:	
    INFO:	o Nice, quarter turn access to battery compartment hatch.

  Longines Symphonette (2500)
    INFO:	o Just like the three types of the 2500.

* TI-2500-II
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   Top Left Side On/Off
                Chain/Constant switch
    BATTERIES:  2-AA
    PHYSICAL:	5.5" x 3.0" x 1.7"
    WEIGHT:	12 ounces
    PRODUCTION:	Introduced November 11, 1974
    COST:	$49.95
    INFO:	o Similar to the 2500 but has a % key and cheap logo 
		  strip that tends to peel off.
		o With a battery hatch?

* TI-2510
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:	xx buttons
    SWITCHES:   Top Left Side On/Off
                Chain/Constant switch
    BATTERIES:  4-AA
    PHYSICAL:	5.5" x 3.0" x 1.7"
    WEIGHT:	12 ounces
    PRODUCTION:	1973
    COST:	$39.95
    INFO:	o Similar to 2500, but chronologically sandwiched 
		  somewhere between the 2500 and 2500-II, probably 
		  failing to land a market niche in TI's crowded 
		  product line.  
		o Calculator body is a lighter cream shade compared 
		  to 2500's beige.  
		o Uses disposable batteries.
		o Nice, quarter turn access to battery compartment hatch.

* TI-2550
    FUNCTIONS:	Four, plus percentage
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   23 buttons
    SWITCHES:   Top Right On/Off
		Top Left Decimal Point Adjust
    BATTERIES:  3-AA NiCads or 4-AAs
    PHYSICAL:	6.5" x 3.2" x 1.8"
    WEIGHT:	10 ounces
    PRODUCTION:	Introduced on January 10, 1974
    COST:	$99.95, later down to $69.95
    INFO:

* 2550-II
    FUNCTIONS:	Four, plus square root, square, reciprocal, and percent
    MEMORIES:	1
    DISPLAY:	8 Vacuum-fluorescent
    KEYBOARD:	27 buttons
    SWITCHES:   Top Right On/Off
                Top Left F/2 Digit 
    BATTERIES:  3 NiCad
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	about 8 ounces
    PRODUCTION:	Introduced on October 17, 1975
    COST:	$49.95
    INFO:

  TI-2550-III
    FUNCTIONS:	Four, plus square root, square, reciprocal, and percent
    MEMORIES:	1
    DISPLAY:	8 Green Vacuum-fluorescent
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  
    PHYSICAL:	5.8" x 3.2" x 1.3"
    WEIGHT:	about 8 ounces
    PRODUCTION:	1976
    COST:	$29.95
    INFO:

  TI-2550-IV
    FUNCTIONS:	Four, plus Playback
    MEMORIES:	1
    DISPLAY:	8 Green Vacuum-fluorescent
    KEYBOARD:	24 buttons
    SWITCHES:   None
    BATTERIES:  
    PHYSICAL:	~5.8" x 3.2" x 1.3"
    WEIGHT:	~about 8 ounces
    PRODUCTION:	1978
    COST:	$
    INFO:	o Info from Thomas Brockmeier

  TI-3500
    Need Info
  
  TI-4000
    twelve digits with commas, and a memory

  TI-5025 (printer)
    FUNCTIONS:	Four plus percentage
    MEMORIES:	1
    DISPLAY:	8 Vacuum-fluorescent
    KEYBOARD:   24 buttons
    SWITCHES:   
    BATTERIES:  xx NiCad
    PHYSICAL:	7.0" x 3.5"
    WEIGHT:	
    PRODUCTION:	1979
    COST:	$89.95
    INFO:	o Portable Display Printer

* TI-5040
    FUNCTIONS:	Four
    MEMORIES:	1
    DISPLAY:	10 Blue Vacuum-fluorescent
    KEYBOARD:   27 keys
    SWITCHES:   Right side, On/Off
		Top right keyboard, F/A format
    BATTERIES:  AC power
    PHYSICAL:	9.4" x 9.25" x 3.0"
    WEIGHT:	~5 lbs
    PRODUCTION:	1977
    COST:	$129.95
    INFO:	o Common desktop model with printer.

  TI-5050
    FUNCTIONS:	Four plus percentage
    MEMORIES:	
    DISPLAY:	None, Paper Tape only
    KEYBOARD:	xx buttons
    SWITCHES:   
    BATTERIES:  xx NiCad
    PHYSICAL:	8.7" x 3.9" x 2.7"
    WEIGHT:	28 ounces
    PRODUCTION:	Introduced on March 24, 1975
    COST:	$199.95
    INFO:	o The TI-5050 was a printing calculator.  It printed 
		  on two-inch wide paper.
		o Handheld printing unit with memory.

  TI-5050M
    FUNCTIONS:	Four plus percentage
    MEMORIES:	
    DISPLAY:	None, Paper Tape only
    KEYBOARD:	23 buttons
    SWITCHES:   
    BATTERIES:  xx NiCad
    PHYSICAL:	8.5" x 4.0
    WEIGHT:	
    PRODUCTION:	1976
    COST:	$99.95
    INFO:

  Able IV
    FUNCTIONS:	Four plus percentage
    MEMORIES:	None
    DISPLAY:	xx LEDs
    KEYBOARD:   16 buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.5" x 2.75"
    WEIGHT:	
    PRODUCTION:	1976
    COST:	
    INFO:	

* Business Analyst
    FUNCTIONS:	Business
    MEMORIES:	None
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:  9 volt rechargable pack
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.25 oz
    PRODUCTION:	Introduced on June 13, 1976
    COST:	$49.95
    INFO:	o The first in a long line of financial calculators.

* Business Analyst I
    FUNCTIONS:	Business
    MEMORIES:	None
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:  2-AA NiCad to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	5.5 ounces
    PRODUCTION:	1979
    COST:	
    INFO:

  Concept I
    FUNCTIONS:	Four plus percentage
    MEMORIES:	None
    DISPLAY:	xx LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Concept II
    FUNCTIONS:	Four plus percentage
    MEMORIES:	yes
    DISPLAY:	xx LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   
    BATTERIES:  9 volt
    PHYSICAL:	5.7" x 2.7"
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Exactra 19
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	6 LEDs
    KEYBOARD:   18 buttons
    SWITCHES:   Left, On/Off
    BATTERIES:  3-AA
    PHYSICAL:	5.25" x 3.0
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Exactra 20 (TI-20)
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	6 LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   Left, On/Off
    BATTERIES:  3-AA
    PHYSICAL:	5.25" x 3.0"
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Exactra 21
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	6 LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   Left, On/Off
    BATTERIES:  3-AA
    PHYSICAL:	5.25" x 3.0"
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Exactra 22
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	6 LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   Left, On/Off
    BATTERIES:  3-AA
    PHYSICAL:	
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

  Exactra 23
    FUNCTIONS:	Four
    MEMORIES:	None
    DISPLAY:	6 LEDs
    KEYBOARD:   xx buttons
    SWITCHES:   Left, On/Off
    BATTERIES:  3-AA
    PHYSICAL:	5.25" x 3.0"
    WEIGHT:	
    PRODUCTION:	
    COST:	
    INFO:	

Exactra 100
    Never released?  

* MBA
    FUNCTIONS:	Business
    MEMORIES:	12
    DISPLAY:	12 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   Top Right On/Off
    BATTERIES:  9 volt rechargeable
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.5 oz
    PRODUCTION:	Introduced on June 5, 1977
    COST:	$79.95
    INFO:	o This was an early business-oriented machine with 
		  several keys for standard business functions.

* Money Manager
    FUNCTIONS:	Business
    MEMORIES:   
    DISPLAY:	8 LEDs
    KEYBOARD:	40 buttons
    SWITCHES:   None
    BATTERIES:  9 volt NICA
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	5.5 oz
    PRODUCTION:	Introduced on January 13, 1977
    COST:	$26.95
    INFO:	o The Money Manager was aimed at home finance calculatins.

* PC-100A (printer)	1979	

* PC-100C (printer)	1979	

* Programmer
    FUNCTIONS:	Four plus Base math
    MEMORIES:	1
    DISPLAY:	8 LEDs
    KEYBOARD:   40 buttons
    SWITCHES:   None
    BATTERIES:  2-AA NiCad to 9 volt
    PHYSICAL:	5.8" x 3.2" x 1.4"
    WEIGHT:	6.25 ounces
    PRODUCTION:	1978
    COST:	$42.50
    INFO:       This calculator was also produced with a LCD display.
(See the "Other Later LCD Models" page for more information). from Arthur Hagen The "TI Programmer" exists in two different versions - one with LEDs and one slimmer one with a LCD display. I still use the latter, and it says Copyright 1978 just like the LED version, although it was produced in the early 80's. As for the price, I paid the equivalent of $120 for it when it was new, but prices here in Norway are much higher. * Spirit of 76 FUNCTIONS: Four plus percentage MEMORIES: None DISPLAY: 8 LEDs KEYBOARD: 19 buttons SWITCHES: Left Side On/Off BATTERIES: 9 volt PHYSICAL: 5.5" x 2.8" x 1.4" WEIGHT: 5.5 ounces PRODUCTION: 1976 COST: INFO: o Red/White/Blue Bicentennial (of the USA) model. o Another 1200 progeny. Tax Planner FUNCTIONS: Complete Tax Functions MEMORIES: DISPLAY: xx LEDs KEYBOARD: xx buttons SWITCHES: BATTERIES: 4-AA PHYSICAL: 6.5" x 3.0" WEIGHT: PRODUCTION: 1983 COST: INFO: o (c) Warren, Gorham, & Lambert o Appears to be a highly modified TI-59


Don't forget to go to my Other Later LCD Models Page


Special Thanks

Andreas Krause (a-krause2@ti.com)
Gene Wright (gene@theporch.com)
Achim Lewandowski (lewandowski@forwiss.de)
Alan Robinson (trw@iland.net)
Andy E (andye@att.com)
Albert Rupprecht (es9j4@yahoo.com)
Arthur Hagen (art@broomstick.com)
Eric (itdept@altrex.nl)
Shaun (loomis@neo.rr.com)
Doug (alwaysup@att.net)
Sebastian (sebastia@flash.net)
Raymond Flowers (Quadrajet1@aol.com)


If you should own a model that I have inaccurately or incompletely described then help me to correct and/or fill in the details. Your E-mails and photocopies are appreciated. We've already discovered 7 previously unknown models: TI-15 (German), TI-31, TI-33, TI-41, TI-42 MBA, TI-45, and the TI-2550-IV. Now if I could only find some for my collection!


The Calculator Reference by Rick Furr (rfurr@vcalc.net)
Back to The TI Calculator Page
Back to The Calculator Reference