HP 33s - Manual (Page 164)

12–6 Simple Programming
5. End the program with a return instruction, which sets the program pointer back
to  ! after the program runs. Press
| – .
6. Press ‡ (or { e ) to cancel program entry.
Numbers in program lines are stored as precisely as you entered them, and they're
displayed using ALL or SCI format. (If a long number is shortened in the display,
press
|  to view all digits.)
To enter an equation in a program line:
1. Press | H to activate Equation–entry mode. The EQN annunciator
turns on.
2. Enter the equation as you would in the equation list. See chapter 6 for details.
Use
b to correct errors as you type.
3. Press ‘ to terminate the equation and display its left end. (The equation
does not become part of the equation list.)
After you've entered an equation, you can press |  to see its checksum
and length. Hold the  key to keep the values in the display.
For a long equation, the ¨ and § annunciators show that scrolling is active for
this program line. You can use — and ˜ to scroll the display.
Keys That Clear
Note these special conditions during program entry:
„ ‡ always cancels program entry. It never clears a number to zero.
„ If the program line doesn't contain an equation, b deletes the current
program line. It backspaces if a digit is being entered ("_" cursor present).
„ If the program line contains an equation, b begins editing the equation. It
deletes the rightmost function or variable if an equation is being entered ("¾"
cursor present).
„ { c { } deletes a program line if it contains an equation.
„ To program a function to clear the X–register, use { c {º}.