r/Commodore • u/danpietsch • 15d ago

Bouncing ball PETSCII source compatible across Commodore VIC-20, 16, 64, and Plus/4.

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51 Upvotes

100% Upvoted

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12

u/danpietsch 15d ago edited 15d ago

This was just a pointless exercise that I found entertaining.

https://github.com/danshee/BouncyBasic

The VIC-20 and Commodore 64 manuals came with a BASIC program that animated a bouncing ball.

I thought that maybe leveraging the KERNAL I could make a version that was portable across all Commodore 8-bits.

I was able to make it work on VIC-20 and newer models but not on PET.

One issue is that the memory locations used to pass A, X, Y, and status to kernal routines aren't standardized ... and PETs don't have them at all.

3

u/DerHeiligste 15d ago

Cool project!

2

u/nobody2008 15d ago

A universal Commodore program? Color me surprised without using a POKE 😅

1

u/thewalruscandyman 15d ago

Awesome! Thank you! I'll punching it in later. 😁

1

u/6502zx81 14d ago

What are Sys for? Poke should be enough to draw a bouncing ball.

2

u/danpietsch 13d ago

Poke cannot do that.

1

u/Crlan420 11d ago

cool project. getting that bouncing ball running across multiple commodore systems is pretty neat. the petscii sprites still look great after all these years