HP 48G - LIBRARY), Ports and Backups

LIBRARY), PorTs AND BAckups
Port memory is different than user memory (where
you normally store variables), in that port memory
cannotbe subdivided into directories, nor can you edit
orview objects stored there. Itis entirely independent
memory—even when everything in main memory is
purged, port memory is maintained—but it can con-
tain just 2 object types: Backup objectsand Libraries.
Port memory may be located in Port 0, Port 1, and/or
Port2, denoted by a (humerical) portidentifier, & port* .
Port 0 is internal to the machine; it is taken out of user
memory, so that any space used as Port 0 reduces
the amount of user memory then available. Ports 1
and 2 exist only in the HP 48GX—if there are RAM
memory cards plugged into those ports.*
Backup Objects
A backup object is named with its port location as well
asanormalname, inthe format ! port* name. To store
any object into a backup object, use with a
backup identifier. Example: To store "Fed" as a
backup object named LColar in PortH, enter "Fed"
onto the stack, then key in : B2 Color and press (STo).
To get a menu of all backup objects currently stored
in a given port, press (&LBRARY) FH, and then se-
lect the desired port (for example, press IETEE now).
A port menu behaves very much like the VAR menu:
To evaluate a backup object, you can eitherkey inits
identifier (e.g. *H:Color) and press (EVAL), or just
press its menu key (e.g. [M). Likewise, to recall
abackup object, either key inits identifier and use (RCL)
or press () and its menu key (e.g. [H). And
to purge a backup object, put its identifier (or a list of
such names) on the stack and use (&JPURG).
To backup all user memory (the entire contents of
HOME directory), first be sure the ticking clock is not
in the display. Then key in a backup identifier (of your
choice) and use the ARCHIVE command. To restore
thisinformation (which replaces all current user mem-
ory), enter its backup identifier and use RESTORE.
*Note that any RAM in card slot 1—where a card is limited to 128 Kb—
may either be merged with normal user memory or left as port memory
(denoted Port 1). But any RAM in card slot 2—where a card is limited
to 4 Mb—must be left as port memory and is partitioned into ports of
128Kb each (i.e. Ports numbered 2-n, where n < 33).
34 THe HP 48G/GX Pocker GuIDE