Calculator User Manual

10-4 Programming
Most features of the TI
.
80 are accessible from programs. Programs can access
all variables and named items. The number of programs that the TI
.
80 can store
is limited only by available memory.
Programs are identified by names of up to seven characters,
beginning with a letter.
A program consists of a series of program commands, which
begin with a
:
(colon). A program command can be an
expression (a command, usually a combination of variables,
functions, and numeric values, that returns a value to
ANS
) or
an instruction (a command, such as
GRIDON
or
PT-ON(
, that
does not return a value to
ANS
).
The TI
-
80 checks for errors when you execute the program,
not as you enter or edit the program.
Variables and lists saved in memory are global; that is, they
can be accessed from all programs. Storing a new value to a
variable or list in a program changes the value in memory
during program execution.
As calculations are made in programs, the TI
-
80 updates
ANS
,
just as it would if the calculations were done on the Home
screen. Programs do not update Last Entry as each command
is executed.
Pressing
´
stops program execution. When you press
´
during program execution, the
ERR: BREAK
menu is
displayed.
¦
To go to where the interruption occurred, select
GOTO
.
¦
To return to the Home screen, select
QUIT
.
The size of programs you can store is limited only by available
memory. To access the
MEMORY
menu, press
2 ¯
from
the Home screen. Memory status is displayed on the
MEMORY
CHECK RAM...
screen. To increase available memory, you can
delete items, including other programs, from the
MEMORY DELETE...
screen (Chapter 12).
Note: Each token in a program takes 1 byte. For example,
SIN 1.23
takes 5 bytes.
About TI-80 Programs
Notes about
Programs
"Breaking" a
Program
Memory
Management and
Erasing
Programs