Retro Review: TI-60X

Retro Review: TI-60X

TI-60X.  Yes I forgot the multiplication sign here.

Company:  Texas Instruments

Years:  1991 – 1995? 2000?

Year of my TI-60X:  1991 (specifically week 46, November 1991)

Type:  Scientific, Formula Storage

Number of Steps: 96, shown in units of registers (12 registers of 8 steps each)

Operating System: Algebraic

Memory Registers: 12 (A through I, X, Y, Z)

Regressions Available:  Linear

Chipset:  Toshiba T9838

Battery: 1 CR2032

My late Uncle Ralph bought a TI-60X for me in 1992 (I think it was in ’92).  It was my first year of high school.  Uncle Ralph encouraged my love for calculators. (Thanks for all you did for me Uncle)

A Rich Feature Set

The TI-60X operates in Algebraic mode.  Simply, type in the expression as its written, and press [ =/ENTER ]. 

The TI-60X isn’t programmable in the traditional sense (keystroke or BASIC) but rather you can store formulas (A = π * B^2, for example) for later use.  I think the TI-60X is the first of its kind to store formulas.  Today, formula storage is a feature of the Sharp EL-520W.  More on this later.

You have your standard linear regression capabilities.  However, instead of the usual labels a, b, and r, you have ITC (intercept), SLP (slope), and COR (correlation) respectively.  If find these labels much helpful since calculators sometimes tend to switch the roles of a and b in linear regression mode.  Entry is rather easy, just enter the data point and press [ Σ+ ] and you are good to go.  No separate declaration of stats mode needed.

Equation:  y = INT + SLP * x

The Base conversions are on the TI-60X as well.  We also get the logical functions AND, OR, XOR, XNOR, NOT, and 2’s (compliment).  The TI-60X distinguishes the variables A-F from the hexadecimal A-F by assigning the latter set to the 3^rd functions of the reciprocal, square, square root, and the trigonometric keys.  On the screen, hexadecimal letters are in bold while storage registers are not.

Fractions are included, as well as the decimal to/from fraction conversion.  The TI-60X has the following additional conversions:

* degrees, decimal-minute-seconds

* polar, rectangular coordinates

* inches, centimeters

* gallons, liters (litres)

* pounds, kilograms

* degrees Fahrenheit (°F), degrees Celsius (°C)

The Blocky Display

Can we talk about the display for a moment?  The text on the TI-60X’s screen is blocky.  According to the Datamath Calculator Museum, the character layout is 5 x 4 dots instead of the usual 7 x 5.  This display could be a throwback to the calculator display of the 1970s and 1980s where the numbers were made of linear segments. 

The article from Datamath on the TI-60X:  http://www.datamath.org/Sci/Modern/TI-60x.htm 

Formula Programming, Simultaneous Equations, and Integration

Up to 12 formulas can be stored, and they can have the labels A, B, C, D, E, F, G, H, I, X, Y, and Z.  The formulas can have more than one variable. Pressing [SOLVE] allow the user to calculate the formula, with each independent variable being prompted.  If there is a numerical value in the independent variable, the TI-60X will display it as a default choice. 

When the “SOLVE YN?” and “REVIEW YN?” prompts appear, the plus key acts as NO and the equals keys acts as YES. 

Integration is pretty easy.  At the appropriate prompted variable, press [2^nd] [ , ] (dx) to insert the dx indicator.  You will be asked for a lower limit, upper limit, and the number of intervals.  I am assuming Simpson’s method but I’m not 100% sure.

Simultaneous equations of 2 x 2 and 3 x 3 linear systems are offered.  Execution takes up 2 or 3 registers respectively.   Solutions are stored in X, Y, and for 3 x 3 systems, Z. 

Example: y = 2 * x * sin x

Enter the formula:

Change to Radians mode by pressing [3^rd] [LOG] (DR>) until the R indicator is displayed. 

Press [2^nd] [ EE ] (FMLA).  At the “NAME?” prompt, press [ ( ] for Y (ALPHA is automatically turned on at this point) and enter the equation.

Calculate y(π/3).  Press [SOLVE].  At X, enter π/3.  Result:  Y = 1.813799364.

Integrate y(x) from 0.5 to 1, use 20 intervals.  Call up the Y= formula again, press [SOLVE].  At the X= prompt, clear the number and enter dx.  Enter the required parameters.  After calculation, the TI-60X displays Y = 0.521068842.  The integral is now stored in Y.

Final Verdict

For what it’s set out to do, the TI-60X accomplishes it rather well.  The calculator is rich with features and there is some storage for some formulas.  I also like the bolder blocky numbers in the display, they are easier to read.  I think the TI-60X launched the advanced scientific calculator genre which is now common place. 

Yes, this calculator is worth collecting.  I’m not sure what the prices are to purchase a used on from eBay, Amazon, or other shopping website, but I imagine it’s not expensive.  (I think the 60X was about $30-$40 when it was sold new back in the 1990s). 

Thank you for comments and support.  Until next time,

Eddie

This blog is property of Edward Shore, 2017.

PCalc 42 User Functions ( iOS )

PCalc 42 User Functions ( iOS )

Programs for the iOS App PCalc 42 from Previous Posts (during May 2014):

http://edspi31415.blogspot.com/2014/05/pcalc-programming-introduction.html

Mohr’s Circle:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp-50g-mohr-circle.html

Period of Orbit Around the Sun:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp-50g-period-of-orbit-around.html

Horizontal Pipe Discharge:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp-50g-horizontal-pipe.html

Newton’s law of Gravity Solver:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp-50g-newton-law-of-gravity.html

Distance of a Star by Parallax:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp50g-distance-of-star-by.html

Escape Velocity:  http://edspi31415.blogspot.com/2014/05/pcalc-and-hp-50g-escape-velocity.html

Time to revisit this app:

PCalc42 Decimal to Degrees-Minutes-Seconds (d.mmssss form): 

D > DMS

Switch to Decimal

Set R0 to X

Truncate X

Set R1 to R0

Subtract X from R1

Multiply R1 by 60

Set R2 to R1

Subtract X from R1

Multiply R1 by 60

Set R2 to R1

Truncate R1

Multiply R1 by 0.01

Add R1 to X

Set R3 to R2

Truncate R3

Subtract R3 from R2

Multiply R2 by 0.006

Add R2 to X

Example:   1.85 in DMS form is 1.51 (1° 51’)

PCalc42 Degrees-Minutes-Seconds (d.mmssss form) to Decimal

DMS > D

Switch to Decimal

Set R0 to X

Truncate X

Set R1 to R0

Subtract X from R1

Multiply R1 by 100

Set R2 to R1

Truncate R1

Subtract R1 from R2

Divide R2 by 60

Multiply R2 by 100

Add R1 to R2

Divide R2 by 60

Add R2 to X

Example:  1.3052 (1° 30’ 52”) in decimal form is 1.514444444

PCalc42 Snell’s Law of Refraction

Input: Y: n1, X: n,  n1 ≤ n2

Switch to Degrees

Invert X

Multiply Y by X

Inverse Sine X

Example:  n1 = 1.33, n2 = 1.50.   Output:  62.4573248455

PCalc42 Doppler Effect (RPN)  (SI Units)

Input:  Z:  emitted frequency (Hz), Y:  receiver velocity (m/s), X: source velocity (m/s)

Output:  observed frequency (Hz) on stack X

Negate X

Add Y to X

RPN Swap

RPN Roll Down

Divide X by 299752458

Add 1 to X

Multiply Y by X

RPN Roll Down

Example: 

Z:  Emitted Frequency:  525 Hz

Y:  Receiver Velocity:  214,000,000 ft/s

X:  Source Velocity:  208,000,000 ft/s

Output:  Observed Frequency:  535.5086711249 Hz

PCalc42 Sums (RPN) Σ m, Σ m^2, Σ m^3

The sum of Σ m^X from m = 1 to m = Y, where X is the power, Y is the power (up to 3).  If Y > 3, an error condition occurs. 

Formulas:

Σ m = (X^2 + X) / 2

Σ m^2 = (2*X^3 + 3*X^2 + X) / 6

Σ m^3 = (X * (X+1))^2 / 4

Set R0 to Y

Truncate X

Skip 3 if X = 1

Skip 7 if X = 2

Skip 16 if X = 3

Error

RPN Roll Down

X To Power of 2

Add R0 to X

Divide X by 2

Stop

RPN Roll Down

X To Power of 3

Multiply X by 2

Set R1 to R0

R1 To Power of 2

Multiply R1 by 3

Add R1 to X

Add R0 to X

Divide X by 6

Stop

RPN Roll Down

Add 1 to X

Multiply X by R0

X To Power of 2

Divide X by 4

Example:

Y = 6, X = 1:  Sum is 21

Y = 6, X = 2:  Sum is 91

Y = 6, X = 3:  Sum is 441

PCalc42 Present Value Factor of a Single Sum

PV:  (1 + Y/100)^-X

Y:  interest rate

X:  periods

Negate X

Divide Y by 100

Add 1 to Y

Y To Power of X

RPN Roll Down

Example:  Y = 7 (7%), X =  5 (n = 5)

Output:  0.7129861795

Happy New Year’s Everyone! See you in 2017!    

Eddie

This blog is property of Edward Shore, 2016.