HP 113394 User Guide - Page 117

Section 8: Programming Basics 117 Interrupting Program Execution Occasionally you'll want a program to stop executing so that you can see an intermediate result or enter new data. The hp 12c platinum provides two functions for doing so: gu (pause) and t (run/stop). Pausing During Program Execution When a running program executes a gu instruction, program execution halts for about 1 second, then resumes. During the pause, the calculator displays the last result calculated before the gu instruction was executed. If you press any key during a pause, program execution is halted indefinitely. To resume program execution at the program line following that containing the gu instruction, press t. Example: Create a program that calculates the entries in the AMOUNT, TAX, and TOTAL columns for each item on the jewelry distributor's invoice shown on the next page, and also calculates the total in each of these columns for all items on the invoice. Assume the sales tax is 6.75%. To conserve lines of program memory, instead of keying in the tax rate before the b instruction we'll store it in register R0 and recall it before the b instruction. Before storing the program in program memory, we'll calculate the required amounts for the first item on the invoice manually. The keystroke sequence will use storage register arithmetic (described on page 29) in registers R1, R, 2 and R 3 to calculate the column sums. Since these registers are cleared when fCLEAR² is pressed, we'll press those keys before beginning the manual calculation - and also later, before running the program - to ensure that the column sums are "initialized" to zero. (Pressing fCLEARH would clear registers R1 through R3, but would also clear R0, which will contain the tax rate.) File name: hp 12c pt_user's guide_English_HDPMF123E27 Page: 117 of 275 Printed Date: 2005/8/1 Dimension: 14.8 cm x 21 cm