C64 Demos peek - Fast any direction bitmap scrolling

In this demos peek video, we look at fast Commodore 64 any direction bitmap scrolling using a combination of HSP/DMA delay and line crunch.
All three parts as one video: • C64 Demos peek - Fast ...
Horizontal scroll: • C64 Demos peek - Fast ...
Vertical scroll: • C64 Demos peek - Fast ...
Example code: github.com/mar...
Codebase link: codebase64.org...
Debugging details text file: github.com/mar...

[@c64customs]

Thanks!

[@MartinPiper6502]

Thank you kindly :)

[@TheStuffMade]

Interesting technique, I learned something new today 👍 I always assumed these large bouncing logos were made from character graphics and moved around using traditional scrolling.

[@MartinPiper6502]

I love this machine. :)

[@ProBloggerWorld]

The demo‘ed effect is top notch. Timing is hard, getting scrolling right with the mapping as well.

[@MartinPiper6502]

yeah the timing is quite tricky, especially for the horizontal movement.

[@OlivierSimpleLife]

Thank you so much for explaining how this great effect works !!! Also à million thanks for sharing the code !!! That's just so kind !!!!

[@MartinPiper6502]

No problem. Sharing is caring. :)

[@luxocrates]

Really appreciate these demo technique dissections. Would love to see more!

[@MartinPiper6502]

Thank you kindly for the support :)

[@retro_noix]

Interesting video
... great to see you venture into investigating demo code tricks! 👍

[@MartinPiper6502]

Glad you enjoyed it!

[@tonibianchetti]

Grazie.

[@MartinPiper6502]

Thank you kindly for the support.

[@delgilchrist]

Does this hardware trick work on all c64 hardware revisions?

[@MartinPiper6502]

Almost all. Some get corrupted memory.

[@phill6859]

​@@MartinPiper6502more than some

[@BobbyCharlz]

So these effects can be used in a proper video game context, or might I need to watch this again (like I’ll do anyway ;)? Space shooter immediately comes to mind.

[@MartinPiper6502]

Yes, this can be used in a game. Some games use the horizontal scrolling method, like Creatures.

[@BobbyCharlz]

@@MartinPiper6502 understood, thank you. I’ll have to take a closer look at the game you’ve mentioned. Great channel and great episodes you’ve got here. I really appreciate the DemoScene decomps that you walk us through. They’re very informative.

[@MartinPiper6502]

I had a video about Creatures using this effect at 24 minutes... ruclips.net/video/DM3Dh3zWoZ8/видео.html

[@BobbyCharlz]

@@MartinPiper6502 Very cool, thank you. Much appreciated.

[@DerykRobosson]

Is the use of Visual Studio that isn't VS Code documented anywhere?

[@MartinPiper6502]

Not as far as I know. I really should document it :)

[@beelinkk]

hahahahaha

[@MartinPiper6502]

Haha

[@beelinkk]

@@MartinPiper6502hahaha

[@MartinPiper6502]

Hahahahaha