Some C64 Games that Weren't!...

[andym00]

*edit*

You're right about colour ram, it's the one thing that can't be double buffered on C64 so if your render requires it you've got to do it at the end as quickly as possible, with something like 3D you could create a double buffer for the info as everything else was being rendered but you'd still have to dump that to the video ram at some point.

 

 

You can kind of double buffer the colour ram, sort of with a bit of VIC jiggery pokery:)

 

If you abort the bad lines every other character line VIC will just display the same colour again, and same character data again, but still advances the colour RAM address regardless..

 

If you swap character sets on these (previously) badlines you can create an 8x16 character matrix with one attribute per character..

You can then swap colour RAMs by doing a line crunch on the first line, or not, so being able to swap between the odd or even lines of colour ram, and with that you have double buffered colour RAM, albeit with half the vertical resolution.. Better than nothing though..

 

Not sure it was ever used in a game, but it is very viable to do and only requires a few (13 or 12) timer interrupts down the screen to work the magic, and when it comes to games scrolling the colour ram gives you lot of leeway that you otherwise don't get when having to blit the colour RAM in as fast as possible..

Edited February 27, 2011 by andym00

[popmilo]

...

Not sure it was ever used in a game, but it is very viable to do and only requires a few (13 or 12) timer interrupts down the screen to work the magic, and when it comes to games scrolling the colour ram gives you lot of leeway that you otherwise don't get when having to blit the colour RAM in as fast as possible..

Could be really usefull in 2d scrolling game. Thanks for that info

 

Really no need why Mood on C64 is not double buffered.

Mood runs in 40x50 resolution and it is simple to do in multicolor bitmap mode.

In that case two colors come from screen memory and that is easily double buffered.

Only reason why they didn't do it would be to speed it up a little.

Triple buffer would solve most of situations without tearing thou.

[PeteD]

Sorry, forgot to post "barring some demo type code that'll only work in very specific cases"

[STE'86]

i thought i may as well attach this link here for anyone wanting to mess with a8 shooter games:

 

4 colour shooter graphics

 

these should be a8 compatible as well as c64.

 

Steve

[gauntman]

Some nice graphics there, thanks!