Radio Shack TRS-80 User Manual page 114

12 IN.
"THE STARTING VERTICAL ADDRESS
*
(
TO
47)
IS"|V
14 IN.
"HDWMANY
VERTICAL BLOCKS DO YOU WISH
TO
FILL";
A
16 IF
V+K48
GOTO
20
18
PRINT "TOO MANY VERTICAL BLOCKS. WOULD WRAP-AROUND!"
19
END
30
FOR
Y =
V
TO V+A
Now
that
we
can draw
straight
lines,
we
can form
figures
—
like squares
and
rectangles.
This
program
forms a
rectangle.
After
NEW
,
type:
10
INPUT
"HORIZONTAL STARTING POINT
(0
TO 127)
"jX
20 INPUT
"VERTICAL STARTING POINT
(0
TO
47)
";Y
30
INPUT
"LENGTH
OF EACH SIDE (IN
BLOCKS)
—
TO 47)
";K
40
CLS
50
FOR
L
=
X
TO X+K
60
SET
(L,Y)
70
SET (L.Y+K)
80
NEXT
L
90 FOR
M
=
Y
TO Y+K
100
SET
£X,H)
1
10
SET
(
X+K,M)
120
NEXT
M
999
GOTO
999
and
RUN
.
Since our
building blocks are not square,
but
2
by
8 rectangles,
we
always get a rectangle.
How
can
we
change
the
program
to
always form a square?
112