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Forum Index : Microcontroller and PC projects : CMM2 - Problem with save image

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joker

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Joined: 06/02/2024
Location: Germany
Posts: 37

Posted: 05:15pm 02 Jan 2026

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Hello,
A happy new year 2026 to you all. :-)

I have this problem since the beginning, but never found time to post it here.

In one of the demo programs, which I studied for the CMM2, a screenshot function was implemented, using save image. I was rather enthusiastic about this feature, so I implemented it in my games, too.

All worked fine until I use 8-bit color mode. In this mode most of the screenshots failed, but interestingly, not all.

It failed also in an awkward way: Only some colors were disrupted or the brightness was set to the lowest level. I attached a screenshot to give you an impression of both effects.

I suppose this has something to do with the CLUT and its write-only feature, but why does it sometimes work and at least some of the custom colors are used in the picture?

I'm totally puzzled. Does anyone of you have an explanation of this?
It could also have something to do with the position in the code. My screenshot command is at the end of the main loop, just after everything has been copied to DISPLAY_PAGE.

It's funny to put it somewhere else. Then certain parts of the picture are missing in the screen shot, but this was clearly my mistake, so ignore it ;-)

Best Regards
Matthias

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