pseudografx Posted January 21, 2014 Share Posted January 21, 2014 It is particularly easy to confuse those two colours 1 and F in Altirra's default PAL palette, where they look identical in all luminances (don't ask me why). And the gameplay videos were probably recorded with Altirra. That is because they ARE identical on real PAL hardware. Atari PAL machines do not really have 256 colours, it's actually only 240 (though there might be some undistinguishable difference in the two hues). Quote Link to comment Share on other sites More sharing options...
Creature XL Posted January 21, 2014 Author Share Posted January 21, 2014 The game is developed for PAL systems only. They might run on NTSC, but lots of sprite flickering should appear and the colors might be off. In PAL there are around 40 empty raster lines extra. And these are needed to draw the sprites. Without these it is not possible to have these sprites in 50Hz. So, if there is not enough raster time the drawing overtakes the raster beam. And in worst case, it takes so long that the next cycles starts. This could result in crashes. "Everything green" is not possible due to the colors. Because I use 1, 14, 11 and 0 in the playing area. These should be distinct on NTSC as well. Maybe a DLI gets skipped (because of the sprite-drawing explained above). Quote Link to comment Share on other sites More sharing options...
+Adam+ Posted January 21, 2014 Share Posted January 21, 2014 That is because they ARE identical on real PAL hardware. Atari PAL machines do not really have 256 colours, it's actually only 240 (though there might be some undistinguishable difference in the two hues). Hmmmm... it seems you're right... I have to spend more time with real machines, not with Graph2Font :/ Is it caused by some bug in PAL version? Quote Link to comment Share on other sites More sharing options...
pseudografx Posted January 21, 2014 Share Posted January 21, 2014 Hmmmm... it seems you're right... I have to spend more time with real machines, not with Graph2Font :/ Is it caused by some bug in PAL version? I think it's due to the design of the formula that is used for generating the palette inside the graphics circuits. It was designed for NTSC system in the first place and PAL support (which changes some variables in the formula due to different frequences) was of secondary importance. Thus the engineers didn't feel it as a serious issue. Therefore it is not a bug, but rather a trade-off. But my deductions may be completely wrong :-) Quote Link to comment Share on other sites More sharing options...
Creature XL Posted January 24, 2014 Author Share Posted January 24, 2014 I am still trying to figure out why everything looks green playing it ntsc, title screen is colorful and nice but the game is not... I tried on several machines. Screen shots show it looks nice and colorful... I will try and see if XE looks different than xl I had a look into this the last days, but couldn't get into the forum to post earlier We are using exactly all green colors from the NTSC palette I made a quick "fix" which uses other colors which look like the PAL version. HOWEVER, this is just to show you how the background would look like. The game is UNPLAYABLE! The reasons for that are explained above. When you leave to the bottom the sprites flicker like hell, this is not the case in the PAL version. When you leave the first room to the left the game hangs! It might be because of the render loop is started while it is still running from the last frame and so the stack gets full. Because of this I haven't changed the sprite colors or the colors in the title screen. Additionally, I will not make it runable on NTSC machines. It is too much work. It is not simply possible to skip a frame. However, I keep the NTSC problem in mind and try to plan for it in a next game. Although an NTSC version has either less sprites or non fluent movement (like TMR mentioned regarding his game) FYI; Colors used in PAL: $1x, $ex, $bx in NTSC: $2x, $fx, $cx HitCEE_NTSC_bkg.xex Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted January 28, 2014 Share Posted January 28, 2014 (edited) It's not just a simple change of color number then?... The other version play/work fine the color was just wrong. I was kind of hoping it was a simple fix like some games used to ask about color and you just choose artifact in some cases or color in other, so maybe a simple start up question to the user, is this screen 1green or 2 red/orange. If red/orange change nothing if green shift pallete number to make red/orange graphics for us. Just plugging in a different number for the start of the color math wouldn't shift it? Edited January 28, 2014 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
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