## Friday, March 30, 2018

### Retro Review: Texas Instruments TI-54

Retro Review:  Texas Instruments TI-54

General Information

Company:  Texas Instruments
Type:  Scientific
Memory:  7 memory registers
Battery:  2 x LR-44 or 2 x AR-76
Years:  1981 - 1983
Original Cost: \$40
Operating System: AOS, Immediate Execution
Storage Arithmetic:  +, -, *, ÷, ^, roots, percent change

It’s good to finally to get the calculator that accompanies the Scientific Calculator Sourcebook that I bought years ago.

Features

The TI-54 is a scientific calculator with a lot of additional features over the typical non-programming scientific calculator that was released at the time.

Percent Key (Δ%)

I think the percent works backwards than modern calculators.   Press the new value first, then [2nd] ( Δ% ), then old value, [ = ].

Example:  Percent change from 32 to 56:  56 [2nd]  (Δ%) 32 [ = ] 75  (75% increase)

Combinations and Permutations

Like the TI-55 III, the arguments for combination and permutation functions take one argument in the form of nnn.rrr.

Example:

Combination where n = 25, r = 5 is entered as 25.005 [2nd] [ 9 ] (nCr)
(Result: 53,130)

Permutation where n = 25, r = 5 is entered as 25.005 [2nd] [ 8 ] (nPr)
(Result:  6,375,600)

Rectangular/Polar Conversion

[2nd] [x<>y] (P-R):  to Rectangular.  Input:  r [x<>y] θ [2nd] [x<>y] (P-R).  Result: y [x<>y] x.

[INV] [2nd] [x<>y] (P-R):  to Polar.   Input x [x<>y] y [INV] [2nd] [x<>y] (P-R).  Result:  θ [x<>y] r.

Statistics

The TI-54 has one variable and two variable statistics, with linear regression of the equation y = a * x + b.   The b/a key gives the intercept and slope.  Predictive values and correlation are also available.

Extra Functions

The TI-54 also has percent change, absolute value, fractional part, and integer part.

Other Functions

Other functions include degree/degree-minutes-seconds conversions and constant operations with [ K ].

Complex Numbers

Perhaps the biggest attraction of the TI-54 is the complex number mode.  Complex mode is activated as soon as the complex number is entered.

To enter complex numbers:

Rectangular:  b [ Img ] a

Polar:  θ [ θ ] r

Since the display is one number, the real part/magnitude is default shown.  To show the complex part, press [ EXC ] [ Img ]/[ θ ] to show the imaginary part/angle.  The user will know if that the imaginary part/angle is shown by the CMPLX indicator is flashing.

The amount of functions to complex functions offered are greater than most scientific calculators would offer, which is impressive at the time:  arithmetic, power, natural logarithms, exponentials, square root, and square.

Keyboard

Scientific calculators that were produced from Texas Instruments in that era (early 1980s) had a reputation for their not so great keyboards, affecting TI-54, TI-55 II, and TI-57.  Unfortunately, the keyboard is the Achilles’ Heel for this model.  On occasion, pressing the key doesn’t register, and occasion the key registers twice.  This problem is prevalent on the number keys.   So operating the TI-54 will require patience and maybe a few extra presses of the [ON/C] key.  Other than this, the TI-54 worked well.

Verdict

If you are to purchase a TI-54, please be aware of possible keyboard issues, other than that it is a good calculator.

Eddie

All original content copyright, © 2011-2018.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.  Please contact the author if you have questions

### Casio fx-CG50: Sparse Matrix Builder

Casio fx-CG50: Sparse Matrix Builder Introduction The programs can create a sparse matrix, a matrix where most of the entries have zero valu...