High-resolution spiraling in Extended BASIC

I figured out how to do this.

Change the step value in line 5 to make the spiral tighter (.2) or wider (.05).

5 ST=.1
20 FOR R=1 TO 165
30 CIRCLE(128,96),R,1,1,S,S+ST
40 S=S+ST:IF S>1 THEN S=S-1
999 GOTO 999

As an experiment, I switched it to PMODE 0 so there could be eight graphics pages of spirals which could be page flipped to make a cool hypnotic animation.

I miss the fun of BASIC.

3 thoughts on “High-resolution spiraling in Extended BASIC

  1. John

    How did you do the PMODE0 page flip trick you mentioned? Will that create an animated spiral a la the opening to The Twilight Zone?

    1. Allen Huffman Post author

      Yes! I did t have it lining up yet, but I did a FOR P=1 TO 8 for each screen the started the spiral, then the next loop it would start at a slightly higher ST value. I just need to tweak it so the page flip animation is smoother. I can share the work in progress code if you want to work on it.

    2. Allen Huffman Post author

      10 PCLEAR 8
      20 ST=.1
      30 FOR P=1 TO 8
      40 PMODE 0,P:PCLS:SCREEN 1,1
      50 FOR R=1 TO 165
      60 CIRCLE(128,96),R+P,1,1,S,S+ST
      70 S=S+ST:IF S>1 THEN S=S-1
      80 NEXT:NEXT
      90 FOR P=1 TO 8:PMODE 0,P:SCREEN 1,1
      100 FOR D=1 TO 50:NEXT
      110 NEXT:GOTO 90


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