Programming Languages: TI85 vs. TI84 CE Plus
I purchased a
1995 edition of the TI85 at a Pasadena City College swap meet. The TI85 was my goto and favorite calculator
through high school (1991 – 1995).
Today, I am
going to compare common programming commands between two of my favorite Texas
Instrument calculators, the TI85 and the current TI84 CE Plus. The manuals for each calculator were
consulted to answer questions.
Arguments in
vector brackets [ ] means the argument is optional.
Command

TI85 (1992 – 1997)
(probably also applies to the TI86)
Software Version 10.0

TI84 CE Plus (2016)
(most of the this applies to TI84
Plus 2004present)
Software Version 5.2.2

Variable
Names

Up to 8
characters, must begin with a number, no spaces.
All variables
are global.

Single
letters A through Z, n, θ
All variables
are global.

Complex
Number display, Rectangular

(X, Y)

X + Yi

Complex
Number display, Polar

(R ∠ θ)

R e^θi

Graphing
Modes

Function,
Polar, Parametric, Differential Equation

Function,
Polar, Parametric, Recurring Sequences

Number of
Colors

0 (monochrome
display)

15: blue,
red, black, magenta, green, orange, brown, navy, light blue, yellow, white,
light gray, medium gray, gray, dark gray (backlit display)
**CE and C
versions only

Input

Input by
itself displays the graph screen
Input [“prompt string”], varname

Input by
itself displays the graph screen
Input [“prompt
string”], variable

Prompt: asking for and storing multiple values

Prompt var1, var2, var3 ,…

Prompt var1, var2, var3, …

Disp

Disp by
itself displays the home screen
Disp var/string, [var/string …]

Disp by
itself displays the home screen
Disp var/string, [var/string…]

Pause

Pause [var/string]

Pause [var/string], [time in seconds]

Wait

N/A

Wait time in seconds up to 100

Display the graph
screen

DispG
displays the
graph screen

DispGraph
displays the
graph screen

Display the
function table

N/A

DispTable

Output

Outpt(line, col, var/string)
8 lines, 21
columns

Output(row, col, var/string)
10 rows, 26
columns

InpSt

InpSt stores entered
text or equations as strings

N/A. Use Input

If – Then –
Else structure

If condition
Then
do if true
[Else
do if false]
End

If condition
Then
do if true
[Else
do if false]
End

For structure

For(var,
begin, end, [step])
commands
End

For(var,
begin, end, [step])
commands
End

While
structure

While condition
do while condition is true
End

While condition
do while condition is true
End

Repeat –
Until structure

Repeat condition
do while condition is false
End

Repeat condition
do while condition is false
End

Menu

Menu(nn, string, label…)
Where nn is
from 1 to 15

Menu(“title”, “text”, label…)
Up to 9
options

Labels
(Lbl/Goto)

Label names
can have up to 8 characters. All
labels are local.

AZ, 0 99, θ. All labels are local.

Increment (by
1) and Skip (if greater to value)

IS>(variable, value)

IS>(variable, value)

Decrement (by
1) and Skip (if less than value)

DS<(variable, value)

DS<(variable, value)

Stop program
execution

Stop

Stop

Return from a
subroutine

Return

Return

Execute a
subroutine

Type the name
of the program

Call program
by pressing [prgm], choosing it from the Program submenu during editing

Clear the
graph screen

ClDrw (clear
all drawings)

ClrDraw
(clear all drawings)

Display text
on a graph screen

N/A

TextColor(color) sets the color.
Text([1], row, col, string)
0164 row
pixel,
0264 column
pixel
1 is for large text

Draw a
temporary function

DrawF f(x)

DrawF f(x), [color]

Draw a
temporary inverse function (f^1(x) = y, x and y are swapped)

DrInv f(x)

DrawInv f(x), [color]

Shading

Shade (lower, upper, left, right)

Shade (lower, upper, [left, right, pattern,
pattern resolution, color])

Draw a line

Line(x1, y1, x2, y2)

Line(x1, y1, x2, y2, [0/1, color, line style])
0/1: 0 to
erase, 1 to draw

Draw a circle

Circle(x, y, radius)

Circle(x, y, radius, [color, line style])

Draw a Point
Only the
TI84 Plus CE has similar commands for pixels

PtOn(x,y)
PtOff(x,y)
PtChg(x,y)

PtOn(x,y, [mark, color])
PtOff(x,y,[mark])
PtChange(x,y,[color])

Convert a
value to a string

N/A

eval(expression) → Str#
No complex
results

Convert a
string to a value

N/A

expr(string)

Convert a
string to a graph variable

St>Eq(string, graph variable)

String>Equ(string, graph variable)

Length of a
string

lngth string

length(string)
(call from
the catalog)

Extract part
of a string

sub(string, begin point, length)

sub(string, begin point, length)
(call from
the catalog)

Execute
Linear Regression analysis (other regressions are similar)

LinR xlist, ylist

LinReg(ax+b) xlist, ylist, [freqlist, Y= variable]

Turn a stat
plot on

N/A (stat
plots are not available on the TI85)

PlotsOn [1,2,3]

Turn a stat
plot off

N/A (stat
plots are not available on the TI85)

PlotsOff [1,2,3]

Turn graph
functions on

FnOn [1 – 99]

FnOn [19, 0]

Turn graph
functions off

FnOff [1 – 99]

FnOff [19, 0]

Notes
As we can see,
the programming language of the TI85/86 family is similar to the TI84 Plus
family, translating the programs should not be difficult. I believe that stat plots are available on
the TI86, but not the TI85.
Keep in mind if
you have complex numbers, that the complex mode on the TI84 Plus (a+bi or re^(θi)
has to be turned on. Furthermore,
logarithmic, power, exponential, and trigonometric functions for complex numbers
return error on the TI84 Plus (substitute expressions must be used).
(use radians
mode)
With z = X + Yi
= R*e^(θ*i), X = real(z), Y = imag(z), R = abs(z), θ = arg(z)
z^n = R^n *
(cos(n*θ) + sin(n*θ)*i), n is a real number
ln (z) = ln R +
θ*i
e^(z) = e^X *
cos Y + e^X * sin Y * i
sin(z) = sin X
* cosh Y + cos X * sinh Y * i
cos(z) = cos X
* cosh Y – sin X * sinh Y * i
sin¯¹ (z) =
asin(z) = i * ln (zi ± √ (1 – z^2)
z1 ^ z2 = e^(z2
* ln z1)
Eddie
This blog is
property of Edward Shore, 2017