Commodore PET User Manual page 110

Now when vou press RETURN, Vou will see the screen blank and the num-
bers begin printing on the second line,
44 44 44 44 44 44 44 44 44 44
44 44 44 44 44 44 44 44 44 44
44 44 44 44 44 44 44 44 44 44
44 44 44 44
44 44
44 44 44 44
44 44 44 44 44 44 44
44 44 44
44 44 44 44 44 44 44
44 44 44
44 44 44 44
44
44
44 44 44 44
44 44 44 44 44 44 44 44 44 44
44
44 44 44 44
44
44 44 44 44
44 44 44 44 44 44 44 44 44
44
44 44 44 44 44 44 44
44 44 44
44 44 44 44 44 44
44 44 44 44
44 44 44 44 44 44 44 44 44
44
44 44 44 44 44 44 44 44 44 44
44 44
44
44
44
44 44 44 44 44
44 44 44 44 44 44 44 44 44 44
44 44
44
44
44
44
44 44 44 44
44 44 44 44 44 44 44 44
44 44
44 44 44 44 44 44 44 44 44 44
44 44 44 44 44 44 44 44 44 44
PHHJ!
READY.
~
To begin printing on the first line, insert a semicolon after the PRINT CLEAR
SCREEN, Change the program now to print characters again, With the extra line
of forty characters, the program can print 840 characters without scrolling any off
the top. Type in the line:
C:t-="A": ';:''':')'',;:
FOR
1= 1
T084€1:
?c:t-.; :
NE>::T: ';:'''PHEl'J' "
The only real change from the original line is the CLEAR SCREEN, The
CLEAR SCREEN adds a nice touch to the display program. The display blanks im-
mediately, instead of gradually scrolling previous text off the top. End the same
line again with the same character. You get a new display with every character
reprinted instead of having duplicate characters appear not to be printed again,
Any of the six cursor control functions can be operated under pro-
grammed control by printing them as string literais. The cursor control string
symbols and keys are Iisted in Table 3-1. Programming cursor controls is de-
scribed in Chapter 5.
A Stored Program
The biggest problem with a program entered in immediate mode is that
you have to reenter it every time you want to run it, as with the display pro-
gram, The solution is to turn it into a stored program.
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