**Retro Review: Texas Instruments TI-35 PLUS**

**Essentials**

Company: Texas Instruments

Type: Scientific

Year:
1986

Battery: A76 x 2

Digits:
10

Memory
Registers: 3, 2 temporary for certain functions and 1 permanent. Storage
arithmetic commands SUM and EXC are included.

Thank
you for Bob Patton. I won this
calculator as one of the door prizes on last week’s HHC 2017.

Like
the last retro review, I am going to describe the features by the modes
available on the calculator.

**Mode 1: Decimal Mode (Normal)**

This
is the normal mode where most of the mathematical operations are available.

The
[ a ] and [ b ] keys are temporary registers for various functions, such as:

Number
of Combinations: n [ a ], r [ b ], [ 2nd
] [ ÷ ] (nCr)

Number
of Permutations: n [ a ], r [ b ], [ 2nd
] [ * ] (nPr)

Rectangular
to Polar Conversions: x [ a ], y [ b ],
[ 2nd ] [ b ] (R>P); r stored in [ a ], θ stored in [ b ]

Polar
to Rectangular Conversions: r [ a ], θ [ b ], [ 2nd ] [ a ] (P>R); x stored
in [ a ], y stored in [ b ]

**Mode 2: Binary Mode**

Entering
Binary Mode converts the number into a binary integer. Arithmetic operations are available. The maximum binary number is 511 (2^9 – 1),
and binary numbers are 10 bits including a signed bit (leftmost).

**Mode 3: Octal Mode**

Entering
Octal Mode converts the number into an octal integer. Arithmetic operations are available.

**Mode 4: Hexadecimal Mode**

Entering
Hexadecimal Mode converts the number into a hexadecimal integer. Arithmetic operations are available. In this mode, the [ sin ], [ cos ], [ tan ], [
1/x ], [ a ], and [ b ] are remapped to the hexadecimal digits A, B, C, D, E,
and F, respectively.

Bob
Patton gives this amazing demonstration of the Hexadecimal mode:

[MODE]
4 [ tan ] [ 0 ] [ b ] [ b ] [ a ] [ a ] [STO]
(stores COFFEE_16 in memory)

[
tan ] [ 0 ] [ tan ] [ 0 ] [ sin ]
(inputs COCOA_16)

Repeat:

[
SUM ] [ 0 ] [ RCL ] [ = ] [ SUM ] [ +/- ]

(Note
what happens while repeating this loop. You
can try a similar key stroke loop on similar calculators. Thank you, Bob!)

**Mode 5: Complex Number Mode**

Store
the real part in temporary register [ a ], the imaginary part in temporary
register [ b ].
Arithmetic operations and polar/rectangular conversions are available. Other math functions work on the components
only.

**Mode 6: Statistics Mode**

The
TI-35 Plus offers 1-variable statistics with the standard measurements of mean,
standard deviation (σn-1), population deviation (σn), and sums. The only way to
clear the stat data is to exit stat mode, then enter it again.

An
added feature is the three normal distribution probability functions. Strangely, these functions do not rely on the
data entered in the stat registers, and assume that the standard parameters
apply (mean is zero, variance is one).

P(t): lower tail probability

Q(t): upper tail probability

R(t): probability from 0 to z

**Keyboard and Display**

The
keys are nice and responsive. Over time
the key markings wearing off. I like the
white font on the dark gray keys. I wish
there was a little more contrast for the secondary functions, which are black
on dark gray.

The
display is nice and crisp.

**Final Verdict**

I
like the TI-35 Plus, it is a step up from the TI-30 series by adding complex
number arithmetic and integer conversions.
However, the TI-35 Plus lacks the Boolean functions found on the
TI-34. It is a matter of what features
are desired.

Eddie

This
blog is property of Edward Shore, 2017.