'$DYNAMIC
SCREEN 13

FOR i% = 0 TO 25
  OUT &H3C8, i%
  OUT &H3C9, i%
  OUT &H3C9, (i% / 25) * 48
  OUT &H3C9, (i% / 25) * 63
NEXT i%

FOR i% = 26 TO 170
  OUT &H3C8, i%
  OUT &H3C9, 25 + ((i% / 170) * 38)
  OUT &H3C9, 48 + ((i% / 170) * 15)
  OUT &H3C9, 63
NEXT i%

FOR y% = 0 TO 199
  FOR x% = 0 TO 319
    zr! = 0: zi! = 0
    cr! = ((x% / 319) * 4) - 2.5
    ci! = (((y% * .625) / 199) * 4) - 1.2
    FOR i% = 0 TO 170
      zrnew! = (zr! * zr!) - (zi! * zi!) + cr!
      zinew! = (2 * zr! * zi!) + ci!
      zr! = zrnew!: zi! = zinew!
      IF ((zr! * zr!) + (zi! * zi!) > 4) THEN
        GOTO exitloop
      END IF
    NEXT i%
    i% = 170
exitloop:
    PSET (x%, y%), i%
  NEXT x%
NEXT y%

DO: LOOP UNTIL INKEY$ <> ""