HP 33s - Manual (Page 40)

1–24 Getting Started
Calculator Memory
The HP 33s has 31KB of memory in which you can store any combination of data
(variables, equations, or program lines).
Checking Available Memory
Pressing { Y displays the following menu:
#  
8

Where
8
is the number of bytes of memory available.
Pressing the {# } menu key displays the catalog of variables (see "Reviewing
Variables in the VAR Catalog" in chapter 3). Pressing the { } menu key displays
the catalog of programs.
1. To enter the catalog of variables, press {# }; to enter the catalog of programs,
press { }.
2. To review the catalogs, press š or ™ .
3. To delete a variable or a program, press { c while viewing it in its
catalog.
4. To exit the catalog, press ‡ .
Clearing All of Memory
Clearing all of memory erases all numbers, equations, and programs you've
stored. It does not affect mode and format settings. (To clear settings as well as
data, see "Clearing Memory" in appendix B.)
To clear all of memory:
1. Press { c {}. You will then see the confirmation prompt 
@ {&} {}, which safeguards against the unintentional clearing of memory.
2. Press {&} (yes).