The display is cleared by other display operations, and by the RND operation if flag 7 is set (rounding to a fraction).

Press fto enter PSE in a program.

The VIEW and PSE lines — or the equation and PSE lines — are treated as one operation when you execute a program one line at a time.

Stopping or Interrupting a Program

Programming a Stop or Pause (STOP, PSE)

„Pressing g(run/stop) during program entry inserts a STOP instruction. This will halt a running program until you resume it by pressing gfrom the keyboard. You can use STOP rather than RTN in order to end a program without returning the program pointer to the top of memory.

„Pressing fduring program entry inserts a PSE (pause) instruction. This will suspend a running program and display the contents of the X–register for about 1 second — with the following exception. If PSE immediately follows a VIEW instruction or an equation that's displayed (flag 10 set), the variable or equation is displayed instead — and the display remains after the 1–second pause.

Interrupting a Running Program

You can interrupt a running program at any time by pressing ‡or g. The program completes its current instruction before stopping. Press g(run/stop) to resume the program.

If you interrupt a program and then press X, {V, or –, you cannot resume the program with g. Reexecute the program instead (X

label).

Error Stops

If an error occurs in the course of a running program, program execution halts and an error message appears in the display. (There is a list of messages and conditions in appendix F.)

Simple Programming 12–17