Chapter 26 - Managing Memory; Memory Structure; The Home Directory - HP 48gII User Manual

Chapter 26
Managing memory
In Chapter 2 of the User's Guide we introduced the basic concepts and
operations for creating and managing variables and directories. In this
Chapter we discuss the management of the calculator's memory in terms of
partition of memory and techniques for backing up data.

Memory Structure

The calculator contains a total of 80 KB to be used for calculator operation
and data storage (user's memory). To see the way in which the user's memory
is partitioned, use the FILES function („¡). A possible result is shown
below:
This screen indicates the existence of one memory port (port 0) which includes
the HOME directory (See Chapter 2 in the User's Guide).
Port 0 and the HOME directory share the same area of memory, so that the
more data stored in the HOME directory, for example, the less memory is
available for Port 0 storage. As mentioned above, the total size of memory
for the Port 0/HOME directory memory area is 80 KB.
Port 0 and the HOME directory constitute the calculator's RAM (Random
Access Memory). The RAM requires continuous electric power supply from
the calculator batteries to operate. To avoid loss of the RAM memory
contents, a CR2032 backup battery is included. See additional details at the
end of this chapter.

The HOME directory

When using the calculator you may be creating variables to store intermediate
and final results. Some calculator operations such as graphics or statistical
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