Epson MX-80 User Manual page 65

Advanced Graphics
Aha! The picture is starting to take shape.
Continue in this manner, moving the colon over one step at a time, then
RUNning. "Step thru" the entire line making only one change at a time, then
RUNning.
GO AHEAD AND DO IT. WE'LL WAIT.
Did you catch the subtle difference in the Error message when STRINGS
didn't READ both its pieces of DATA? Did you see LPRINT do its thing
when the " 0 " was acted upon? If not, best you go back thru line 90 and do
this assignment again to get the full impact of the program's development.
There's a lot of work involved in such a project, isn't there? It obviously re-
quires careful planning (or an awful lot of cut-and-try). Since you get the idea,
step thru the rest of the DATA entries (coming up) in this same fine detail
only if you really want to.
Continuing On
Everybody add 2 more lines:
60 L P R I N T T A B ( 4 0 ) C H R $ ( 1 4 ) " B A S S CLEF MUSIC C O . " : RETURN
1 0 0 DATA 1 5 7 , 1 9 1 , 1 4 0 , 1 4 0 , 1 7 5 , 1 4 , 1 4 0 , 1 5 6 , 6 , 1 4 0 , 1 7 4 , - 1
and RUN.
Very nice. The " - 1 " at the end of the DATA line sent us off to LPRINT the
message in line 60 — in Double Width. Double width, as we remember, shuts
itself off at the end of any line in which it is used.
Let's type in 2 more lines:
7 0 L P R I N T T A B ( 5 0) " 8 1 6 HARMONIC WAY" : RETURN
1 1 0 DATA 1 8 1 , 1 7 8 , 1 7 9 , 1 7 6 , 1 8 6 , 1 7 8 , 1 7 7 , 1 2 , 1 7 6 , 1 8 1 , 6 , 1 7 6 , 1 8 6 , - 2
and RUN.
Getting better. The " - 2 " was snagged by the ON-GOSUB in line 50 and
execution routed to line 70, which very routinely printed it.
Two more lines:
80 L P R I N T T A B ( 5 1 ) "MUSICTOWN, USA" : RETURN
1 2 0 DATA 1 4 9 , 1 2 8 , 1 6 0 , 1 5 2 , 1 3 5 , 1 2 , 1 2 8 , 1 8 4 , 1 8 8 , 1 4 9 , 6 , 1 2 8 , 1 7 0 , - 3
and RUN.
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