GP2X Screen Corruption

[[hjd_uk]]

Hi, i've recently noticed a draw problem in the GP2x, in some demo programs but also the photo viewer.

The last 8 or so pixels in the screen (bottom right) and sometimes the top left few are getting drawn incorrectly.
Seems the pixels are coming from elsewhere in the buffer / image. They change with the main image.

Anyone else noticed this?, I have firmware 1.2.1.

 

[Radek]

Hi, i've recently noticed a draw problem in the GP2x, in some demo programs but also the photo viewer.

The last 8 or so pixels in the screen (bottom right) and sometimes the top left few are getting drawn incorrectly.
Seems the pixels are coming from elsewhere in the buffer / image. They change with the main image.

Anyone else noticed this?, I have firmware 1.2.1.

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If they are showing randomly then you have probably a defective ram memory in your gp2x. Anyway it's reason to complain and demand realization of warranty.

 

[gfoot]

The hardware blitter doesn't seem to like writing the last few pixels at the bottom right of the screen, and we use a dummy write to the top left to clear out its cache after each blit. I got the dummy write wrong in Allegro I guess - is that what you're using? I generally get a black link up there IIRC. The bottom right corner of the screen tends to get a copy of something from somewhere else, very consistently - I'm not sure exactly what it's duplicating though.

It's interesting if you say this happens in the photo viewer, as that means it may be a more fundamental problem with the blitter. :/

 

[paeryn]

Those few pixels in the bottom right aren't coming from the screen memory. If you switch the scaler on with minimal scaling the pixels go back to what they should be, switch off the scaler and they'll re-appear.
It can't be a problem with how we're using the blitter as the menu shows this effect on mine - that's just from switching it on before I run any programs.

 

[BBTroll]

I have seen it on STerm. When you have the character selection curson on '9' or 'a', they will show up. Pixels 58 through 68 are moved to the last 8. Strange.

 

[[hjd_uk]]

It doesnt seems to be random, its always the last few pixels and they get copied from a consistant source, Its noticible on the Parallax demo.