Tom Posted October 28, 2003 Share Posted October 28, 2003 one thing i don't really understand is how you get all the vertical timing stuff *correct*: according to the stella manual, you do it like this: - generate 3 lines of vsync, by setting VSYNC to 2 for the duration of 3 scanlines - generate 37 lines of vblank, by setting VBLANK to 2 for the duration of 37 lines - draw your image (192 or 242 lines) - 30 lines of overscan what confuses me is the vblank stuff: in the tutorials, VBLANK is set to 01000001b during overscan, vsync and vblank period. so what's correct now ? or doesn't it matter at all ? and why is bit 6 of VBLANK set ? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted October 28, 2003 Share Posted October 28, 2003 what confuses me is the vblank stuff: in the tutorials, VBLANK is set to 01000001b during overscan, vsync and vblank period. so what's correct now ? or doesn't it matter at all ? and why is bit 6 of VBLANK set ? Bit 6 dumpes (resets) the paddles ports. So it is only necessary for paddle games, but there is no problem if you also set it for joystick games. Quote Link to comment Share on other sites More sharing options...
EricBall Posted October 28, 2003 Share Posted October 28, 2003 See Session 13: Playfield Basics for my comments about the VBLANK control bits and some other comments about VBLANK usage. Quote Link to comment Share on other sites More sharing options...
Tom Posted October 28, 2003 Author Share Posted October 28, 2003 EricBall: yeah, that cleared everything up, thanks Quote Link to comment Share on other sites More sharing options...
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