Radio Shack TRS-80 - Page 112

Answer:
10
CLS
20
FOR
Y
=
47
TO
STEP-1
30
FOR
X
= TO
127
40
SET
(X, Y)
50
NEXT
X
60
NEXT
Y
99
GOTO
99
OK,
now
rewrite
it so it
starts
painting at
the right-hand side
and
fills to
the left-hand
side.
Answer:
10
CLS
20
FOR X
=
127 TO
STEP-1
30
FOR Y
=
TO
47
40
SET
tX,
Y)
50
NEXT
Y
60
NEXT X
99
GOTO
99
Fantastic
—
now
you
can paint
the old barn at
least
4
ways!
EXERCISE
20-1
: Write a
program
which will
allow
painting
only
a
small
part of the
screen
(you
determine
which part).
Allow
keyboard
INPUT
of the
starting and
ending block
num-
bers in
both
the
horizontal
and
vertical directions.
DWa
t know
1
y
m
could
STEP
it
MCfcw&rds^ehT
Try-
a
few
of
those and
see how it
works. Try
;
different
increments (-2,
~S, etc,),
'^
:
0.
^
'-
.'.^
Try
same
other
step
increments too,
110