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berighteous
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Joined: 18/07/2020
Location: United States
Posts: 110

Posted: 10:49pm 17 Aug 2020

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Hi all!
I have found a glitch in page copy in mode 3,8 when the frame buffer is activated and pagebuffer write is set �Page copy x to 0 copies the top half of the page you want and the bottom half of page 7 in this case. If page write is set to any normal page (like page write 3) it works fine.

before activating and backing up a 333x292 frame buffer. Page copy 2 to 0, 3 to 0, etc.

and after. �I did a slide show in the program after the frame buffer was initialized, setup and backed up, but before the animation of everything started.

the pages are correct, but page copy isn't. �All the art is in place and working

Hey look! I have masked multicolored text now...
Edited 2020-08-18 16:48 by berighteous

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10580

Posted: 09:01am 18 Aug 2020

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Thanks for the report - will fix in b11.

This results from the way the lower resolution screens are generated. 320x200 is actually 320x400 with all lines duplicated so the page uses 320x400 = 128000 bytes. For efficiency and memory reasons the lines are not duplicated in the framebuffer so the code switches off duplication when page writes are to the framebuffer. HOWEVER, in your case although page writes are to the framebuffer the page copy command is not using it and hence..........

The workround is to set PAGE WRITE to something other than the framebuffer before doing the page copy and then set it back when needed
Edited 2020-08-18 19:05 by matherp

berighteous
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Joined: 18/07/2020
Location: United States
Posts: 110

Posted: 09:06am 18 Aug 2020

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I saw that. I had just set the framebuffer up and copied the background to it and didn't set the page write because copy page doesn't need it usually.

I'm moving all the asteroids and stuff on the frame buffer which is bigger than the background nebula, so the asteroids have room to go off the background but still remain in the framebuffer area. Then I neatly crop out the nebula and copy it to another page where I add the overlays and whatall before page copying it back to page 0. Works great.

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