Parallax Scrolling on Atari 8bit computers

This example show how a Atari can do parallax scrolling on four directions.

[@DTM-Books]

Looks amazing. I'd love to see someone make a working game demo out of that tech. But I'm sure that would be especially challenging with the ancient Atari 800 hardware. Great work!

[@renderizer01]

It's not that difficult, really. The vertical and horizontal scrolling of the playing field was very easy to achieve on the Atari. The parallax effect is achieved by vertically or horizontally shifting (or scrolling) the 4x8 bitmap that makes up the 'empty' or background character (the whole playing field is made up of an altered character set) in half time in relation to the scrolling of the playing field. You could also compose the 'background' from more characters (say, 2x1 of even 2x2). Looks more complex than it really is. Which is the trick. ;O)

[@irataatari9610]

nieźle ! awesome !

[@gazzaka]

I would it can be easily done using multiple char sets

[@ULTRAWEN7]

Круто!

[@SoloKazama]

but its atari xl/xe :)

[@AGWhiteman]

Like to see what you can do with an Atari STe!

[@jrherita]

STe would have to brute force this -- maybe use the blitter chip to help. The Atari 8bit can do this natively thanks to ANTIC :)

[@przemekkobel4874]

@@jrherita Well yes and no. STe was a little bit more friendly in video memory addressing, so vertical scrolling could be done all in hardware, and horizontal could be somewhat assisted. Other thing is that on ST people could brute-force only parts of the memory, like only some bitplanes instead of the whole thing. This way you could have moving stuff on every part of the screen area while touching only 1/4 or 1/2, or 3/4 of actual memory. It was significant since even by using fastest possible method (lots of MOVEM commands), you couldn't transfer whole screen area by CPU in a single frame . And despite all that, we have things like Dark Side Of The Spoon (demo), or Enchanted Land (game).

[@SteveMorrow8859]

I have a question for mcapp. Are you pretty efficient using assembly language? Did you make this cool fine scrolling example for parallax scrolling? If you did I would like to get in touch with you. I have started a recent KZbin channel on assembly language programming for the Atari 8-bit computer, however I am still on the surface of learning how to fine scroll. I see you have perfected it here. Nice job. Check out my channel and tell me what you think. Then please contact me.