How to generate Lottery Numbers on the Commodore 64

In this video I’ll demonstrate how to draw random lottery numbers on a Commodore 64. The secret sauce here is not only the RND function to generate random numbers, but also two loops inside each other that prevent the same number from coming up more than once.

Here’s the lottery generator code:

10 x=rnd(-ti)
20 for i=1 to 6
30 rn=int(rnd(1)*49)+1
40 for j=1 to i
50 if n(j)=rn then 30
60 next j
70 n(i)=rn
80 next i
100 print
110 for i=1 to 6
120 print n(i);
130 next
140 print
199 end

To adapt this listing to match your local lottery, change line 20 to the amount of numbers to be drawn from your pool (6 in my example), and change the value in line 30 to match the size of your pool (49 in my example).

Any questions, please let me know below.

Happy retro hacking!

Jay is founder of WP Hosting, a boutique style managed WordPress hosting and support service. He has been working with Plesk since version 9 and is a qualified Parallels Automation Professional. In his spare time he likes to develop iOS apps and WordPress plugins, or drawing on tablet devices. He blogs about his coding journey at and

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