HP (Hewlett-Packard) 12C ユーザーズマニュアル

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112  Section 8: Programming Basics 
 
 
File name: hp 12c pt_user's guide_English_HDPMF123E27  Page: 112 of 275   
Printed Date: 2005/8/1   
Dimension: 14.8 cm x 21 cm 
 
The 
000 Instruction and Program Line 000 
Whenever you run the program now stored in program memory, the calculator 
executes the instruction in line 008 after executing the seven instructions you keyed 
in. This i000 instruction — as its name implies — tells the calculator to “go to” 
program line 000 and execute the instruction in that line. Although line 000 does 
not contain a regular instruction, it does contain a “hidden” instruction that tells the 
calculator to halt program execution. Thus, after each time the program is run, the 
calculator automatically goes to program line 000 and halts, ready for you to key 
in new data and run the program again. (The calculator is also automatically set to 
program line 000 when you press fs to set the calculator from Program mode 
to Run mode or when fCLEARΠis pressed in run mode.) 
The i000 instruction was already stored in line 008 — in fact, in all program 
lines — before you keyed in the program. If no instructions have been keyed into 
program memory, if Continuous Memory is reset, or if fCLEARΠis pressed (in 
Program mode), the instruction i000 is automatically stored in program lines 
001 through 008. As you key each instruction into program memory, it replaces 
the i000 instruction in that program line. 
If your program should consist of exactly eight instructions, there would be no 
i000 instructions remaining at the end of program memory. Nevertheless, after 
such a program is executed the calculator automatically returns to program line 
000 and halts, just as if there were a i000 instruction following the program. 
If you key in more than eight instructions, program memory automatically expands 
to accommodate the additional instructions. 
Expanding Program Memory 
If no instructions have been keyed into program memory, if Continuous Memory 
has been reset, or if fCLEARΠhas been pressed (in Program mode), program 
memory consists of 8 program lines, and there are 20 storage registers available 
for storage of data.