Subject: Re: [stella] GunFight 2600: Limit broken again! Now help needed! :-) From: Manuel Polik <manuel.polik@xxxxxxxxxxx> Date: Fri, 16 Feb 2001 14:53:49 +0100 |
Eckhard Stolberg wrote: > > And: can someone give me a crash course in clever missile programming? I > > mean, do I really have to tweak ENAMx all the time? what about just > > making the missile invisible with the background color? > As long as there is nothing above or below the cowboy, you can disable > the missile by changing it's colour. But if you try to make the > background more interesting by adding some playfield graphics for > example, a recoloured missile would stand of against the playfield, > if you don't turn it off properly with ENAMx. I have to consider this... All depends a bit on how many cycles I can free with a 2LK. At the moment I just see that I win nothing in the color-writes. I'd have to do 4 writes in each line, gaining only few cycles by buffering these values. > If we call the registers GRP0-A, GRP0-B, GRP1-A and GRP1-B, > then the graphics work like this. The A registers are what > you write to when you store something to GRPx. But when you > for example do STA GRP0, not only gets the contend of the > accumulator copied to GRP0-A, also the contend of GRP1-A > gets copied to GRP1-B. With STA GRP1 you also copy the > contend GRP0-A to GRP0-B. > VDELx lets you select, if you want to display GRPx-A or > GRPx-B. So all graphics are just shifted one line down. And what's the gain? If I understand that right, you have still to do the right timing, then starting from the second write, or? What I have in mind ATM is one line with data calculations/fetches/bufferings(and color writes *sic*) and a second line with writes. This'd help more than delaying, or? Greetings, Manuel - Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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