Wrathchild Posted December 19, 2005 Share Posted December 19, 2005 Hi, In playing AR: The Dungeon's intro under emulation, my ears don't like the tune played at 50Hz and find it much better at 60Hz. Whether or not patching it to auto-detect the machine's rate and playback accordingly would actually fix this is possible, it got me thinking that a list could be compiled of those titles that people know have issues and maybe during 2006 the programmers amongst us can hack some of them to work correctly. I guess games with timers, e.g. counting down, could suffer this problem and playing it in one country either puts one user at an advantage, e.g. more time than was originally intended, or at a dis-advantage, e.g. the game runs out sooner than it normally would. I would be good to also confirm the games that check this correctly and adapt accordingly. Regards, Mark Quote Link to comment Share on other sites More sharing options...
Goochman Posted December 19, 2005 Share Posted December 19, 2005 As we found out in the High Score Club Pole Position has this problem. Its hard to break 106K in NTSC mode but 114K+ is quite easily achieved under PAL mode. I would presume anything timer bonus related will have an issue. Quote Link to comment Share on other sites More sharing options...
emkay Posted December 21, 2005 Share Posted December 21, 2005 Sea Dragon That game gets boring slow when playing it at 50Hz. Popeye It makes more fun at 60Hz Salmon Run At 50Hz you cannot escape the Bears, when it is possible at 60Hz. Quote Link to comment Share on other sites More sharing options...
Rybags Posted December 21, 2005 Share Posted December 21, 2005 Most games use timers based on the VBI. Although you can get near identical timing using POKEY, I feel it to be a bit of a waste of time, plus you lose the use of 1 sound voice. Of course, well written software could use fractional increments for sprite movement, and other techniques to keep music the same speed, but in my experience, I haven't really come across any such software. Machines like the ST and C-64 had the advantage of 100Hz timer interrupts which were built in to the OS/HW, but games tend to ignore them since they're not based on the VBlank interval. Quote Link to comment Share on other sites More sharing options...
Plastron Posted December 23, 2005 Share Posted December 23, 2005 In my games i used $14 as the way of moving items without screen flicker so i guess they will all run faster on a 60Hz machine. loop lda $14 cmp $14 beq loop If you do this before any screen action results will be flicker free. But timing is different 50 to 60 Hz Andy Quote Link to comment Share on other sites More sharing options...
Rybags Posted December 23, 2005 Share Posted December 23, 2005 (edited) One of the big problems with the older computers is that moveable objects are usually 2D sprites with a fairly defined pattern, as compared to more modern games with anti-aliased 3D textured objects. Once you start moving objects at fractional rates (which you would have to do to get the same speed with PAL/NTSC) you can really see some jerkiness coming in. I found that I could get the best sprite movement using the following method for velocity control. Imagine the sprite as having a byte as follows for velocity: 76543210 DIIIFFFF D is a direction flag (1=left, 0=right) III is the increment component. The number of pixels per frame to move the object to the left or right (as flagged by D). FFFF is a fractional component. It gets added to a 4-bit counter. If the counter overflows, then for that frame only, add 1 to the increment component. With variations of that technique you can have multiple objects with unique speeds, and not have to use too much processing overhead. Edited December 23, 2005 by Rybags Quote Link to comment Share on other sites More sharing options...
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