CIRCLE draws a circle of given radius at the specified coordinates.
CIRCLE [(X,Y,)] ,r[,n]
10 FOR I = 20 TO 220 STEP 40 20 CIRCLE (1,32), 20 30 NEXT
Will plot six circles across the display.
The optional parameter n will plot the circle in black if it is odd, or erase the points if it is even. When omitted, it defaults to odd. The co-ordinates may also be omitted, and the circle is then centered on the current graphic cursor position. Circles plotted off the edge of the screen will produce wrap around, Modulo 256.
The CIRCLE command range checks the x-coordinate, y-coordinate and radius to be less than 256. Since the HUNTER screen in graphics mode can only display 0-239 and 0-63 in the x and y directions respectively, there are occasions when the expected circle does not appear on the screen.