**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 [2

^{nd}] ( Δ% ), then old value, [ = ].
Example: Percent
change from 32 to 56: 56 [2

^{nd}] (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 [2

^{nd}] [ 9 ] (nCr)
(Result: 53,130)

Permutation where n = 25, r = 5 is entered as 25.005 [2

^{nd}] [ 8 ] (nPr)
(Result: 6,375,600)

**Rectangular/Polar Conversion**

[2

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

^{nd}] [x<>y] (P-R): to Polar. Input x [x<>y] y [INV] [2^{nd}] [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