Atarigmr Posted February 28, 2012 Share Posted February 28, 2012 Hi I have started to play with some ataru 8 bit coding and I have ran into a problem, I am trying to have a widescreen with 240 lines (30 lines of which are mode 2 and the others mode 4), but it flickers, it only works with 232 lines, my dlist is: dlist dta $42,a(vram),2,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,$41,a(dlist) What am I doing wrong? thx Quote Link to comment Share on other sites More sharing options...
phaeron Posted February 28, 2012 Share Posted February 28, 2012 Your display list is actually 241 scanlines tall -- the JVB instruction ($41) occupies a blank line. If you aren't rewriting DLISTL/DLISTH every frame, you're alternating between what you wanted to see and a completely blank frame. Quote Link to comment Share on other sites More sharing options...
Atarigmr Posted February 28, 2012 Author Share Posted February 28, 2012 Thank you a lot phaeron, it is working fine now Quote Link to comment Share on other sites More sharing options...
Atarigmr Posted April 9, 2012 Author Share Posted April 9, 2012 I have found that I need two more lines , is it possible to have a 40x32 chars mode? If so would it be tricky to set up? Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 9, 2012 Share Posted April 9, 2012 40 x 30 is normally the max - but you can get problems if the 240th scanline is in hires. There's a fix for it, involves using a DLI to play about with DMACTL at the right times. You can create shortened characters using DLIs and VSCROL register changes. So, e.g. if you have 6 pixel high chrs instead of 8 that means possibly 40x40. My interlaced demo raises the usable resolution to 480 pixels instead of 240. 8 pixel high chrs could be done at 40 x 60 although they're half normal height and might be a bit hard to read. Easist fix for you would be just use VSCROL tricks. You could get away without needing custom character sets by doing 7 pixel high characters. 240 / 7 gives 34 character rows with a few scanlines left over. Quote Link to comment Share on other sites More sharing options...
Atarigmr Posted April 9, 2012 Author Share Posted April 9, 2012 Thank you for clarifying things Rybags. Shorter chars are not an option but I have come with an idea but I don't know if it will look ok - the extra lines were to be top and bottom game stats but I can have the game area a bit smaller(horizontally) and then have some columns on the sides free where I would have the score and other stats displayed vertically but this might be impractical as it might be hard to read also if I want to have some displaylist interrupts to get more color this will affect the stats too... hmmm Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 9, 2012 Share Posted April 9, 2012 You don't have to do it for the whole screen. You could make a special font and just have short chars for a few lines top/bottom. Or you could just use bitmap and render chars by software. Quote Link to comment Share on other sites More sharing options...
Atarigmr Posted April 9, 2012 Author Share Posted April 9, 2012 Thx Rybags, I have chosen char mode because I can have the 5th color. The 30 lines of the play area must be 8 pixels high each. Quote Link to comment Share on other sites More sharing options...
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