HP 49g+ - Manual (Page 774)

Page 26-9
After installing the library contents in port memory you need to attach the
library to the HOME directory. This can be accomplished by rebooting the
calculator (turning the calculator off and back on), or by pressing,
simultaneously,
$C. At this point the library should be available for use.
To see the library activation menu use the LIB menu ( ‚á). The library
name will be listed in this menu.
Library numbers
If you use the LIB menu ( ‚á) and press the soft menu key corresponding
to port 0 or 1, you will see library numbers listed in the soft menu key labels.
Each library has a four-digit number associated with it. These numbers are
assigned by the library creator, and are used for deleting a library.
Deleting a library
To delete a library from a port, use:
• In algebraic mode: PURGE(:port_number: lib_number)
• In RPN mode: : port_number : lib_number PURGE
Where lib_number is the library number described above.
Creating libraries
A library can be written in Assembler language, in System RPL language, or
by using a library-creating library such as LBMKR. The latter program is
available online (see for example, http://www.hpcalc.org). The details of
programming the calculator in Assembler language or in System RPL language
are beyond the scope of this document. The user is invited to find additional
information on the subject online.
Backup battery
A CR2032 back up battery is included in the calculator to provide power
backup to volatile memory when changing the main batteries. It is
recommended that you replace this battery every 5 years. A screen message
will indicate when this battery needs replacement. The diagram below shows