Texas Instruments PLUS TI-89 - Manual (Page 381)

364 Chapter 21: Memory and Variable Management
21MEMORY.DOC TI-89/TI-92 Plus:Memory & Variables Mgmt (English) Susan Gullord Revised: 02/23/01 1:20 PM Printed: 02/23/01 2:19 PM Page 364 of 16
The Memory Error message is displayed if there is not enough free
RAM to access the archived variable. This may cause you to ask, “If
the variable is in the user data archive, why does it matter how much
RAM is available?” The answer is that the following operations can
be performed only if a variable is in RAM.
¦ Opening a text variable in the Text Editor.
¦ Opening a data variable, list, or matrix in the Data/Matrix Editor.
¦ Opening a program or function in the Program Editor.
¦ Running a program or referring to a function.
So that you don’t have to unarchive variables unnecessarily, the
TI -89 / TI-92 Plus performs a “behind-the scenes” copy. For example, if
you run a program that is in the user data archive, the
TI -89 / TI-92 Plus :
1. Copies the program to RAM.
2. Runs the program.
3. Deletes the copy from RAM when the program is finished.
The error message is displayed if there is not enough free RAM for
the temporary copy.
To free up enough RAM to access the variable:
1. Use the VAR-LINK screen ( 2 ° ) to determine the size of
the archived variable that you want to access.
2. Use the MEMORY screen ( 2 ¯ ) to check the RAM free size.
3. Free up the needed amount of memory by:
¦ Deleting unnecessary variables from RAM.
¦ Archiving large variables or programs (moving them from
RAM to the user data archive).
Memory Error When Accessing an Archived Variable
An archived variable is treated the same as a locked variable.
You can access the variable, but you cannot edit or delete it.
In some cases, however, you may get a Memory Error when
you try to access an archived variable.
What Causes the
Memory Error?
Note: As described below, a
temporary copy lets you
open or execute an archived
variable. However, you
cannot save any changes to
the variable.
Note: Except for programs
and functions, referring to
an archived variable does
not copy it. If variable ab is
archived, it is not copied if
you perform 6
ù ab .
Correcting the Error
Note: Typically, the RAM
free
size must be larger than
the archived variable.