Commodore PET User Manual page 390

Program 8, PRINTOVER
1.
5 REM PROGRAM 8 PRINTOVER 1
10 REM ~**~~*~ B LAN K E T ~**~***
20 REM CONTINUOUS-LINE DISPLAY OF ONE
30 REM CHARACTER ENTERED FROM THE
40 REM KEYBOARD
50 REM
**~**.*.*****.*************.***
90 PRINT"HIT A
tŒ'T'
OR -CR:> TO END".;
10(1 GET C$; 1F C$="" GOTO 100
105 IF C$=CHR$(13) GOTO 170
11 (1 PR 1NT ":']" ; ; REM CLEAR SCREEN
120 FOR 1=1 TO 4 ;REM 230*4=23 LINES
130 PRINT C$;
140
NE>~T
150
PRIt-n"PHE~·J!"
160 GOTO 90
17(1
E~m
Changes
Add:
Change:
Delete:
Line 5
Line110
None
Comments
This is the easiest program modification so far - just change the Clear
Screen literai at line 110 to a Home Cursor!
However, the pragram display suffers fram two things caused by not blank-
ing the screen. First. there may be extraneous characters left in the bottom two
rows that are not blanked out or overwritten by the program; this is because the
PHEW! and HIT A KEY messages don't coyer the entire lines, nor does the PET
blank out the rest of the lines. Second, the character display appears not to move
if the same character is keyed in again; this also holds for the two messages
printed at the bottom of the screen. For this pragram's purposes, vou would prefer
to see some movement at the cursor position when printing a character over the
same character.
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