HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 163

For output, you can display a variable with the VIEW instruction, you can display a message derived from an equation, or you can leave unmarked values on the stack. These are covered later in this chapter under "Entering and Displaying Data." Entering a Program Pressing { e toggles the calculator into and out of Program-entry mode - turns the PRGM annunciator on and off. Keystrokes in Program-entry mode are stored as program lines in memory. Each instruction or number occupies one program line, and there is no limit (other than available memory) on the number of lines in a program. To enter a program into memory: 1. Press { e to activate Program-entry mode. 2. Press { V   to display  !. This sets the program pointer to a known spot, before any other programs. As you enter program lines, they are inserted before all other program lines. If you don't need any other programs that might be in memory, clear program memory by pressing { c {}. To confirm that you want all programs deleted, press {&} after the message 3. Give the program a label - a single letter, A through Z. Press { • letter. Choose a letter that will remind you of the program, such as "A" for "area." If the message is displayed, use a different letter. You can clear the existing program instead - press { Y {}, use ™ or š to find the label, and press { c and ‡. 4. To record calculator operations as program instructions, press the same keys you would to do an operation manually. Remember that many functions don't appear on the keyboard but must be accessed using menus. Programs written for ALG mode should normally have an "=" (ENTER) as the last instruction in the program (before the RTN instruction). This will complete any pending calculations and allow the user to re-use the result of the program in further calculations. To enter an equation in a program line, see the instructions below. Simple Programming 12-5