HP 7470A Interfacing And Programming Manual page 56

Lines 20 and 30 define the plotting area and perform user-unit scaling.
Line 40 moves the pen to point (+800,800)to locate the starting point of
the first pattern.
Lines 130 and 140 contain the subroutine necessary to draw the
pattern. First, a 50-unit radius circle is drawn, followed by a relative
move of 600 units in the X—directionwhere another 50—unitradius
circle is drawn. A move of —300units in X and -300 units in Y
locates the center of the 250—unit c ircle. The last two 50-unit circles
are drawn with the moves shown in the listing.
Lines 60, 80, and 100 locate the starting points of the other three
patterns.
START
PA (—800,800)
PA (200,800)
PA (-8o0,—200) PA (200,—200)
O O O O
O O O 0
3-16 CONTROLLING THE PEN AND PLOTTING