Subject: Re: [stella] Z26 vs. Oystron From: Piero Cavina <p.cavina@xxxxxxxxxxxxx> Date: Mon, 19 Jan 1998 12:26:53 +0100 (MET) |
At 09.05 18/01/98 -0800, you wrote: >>Today, trying Z26 for the first time (a 32K program?!... wow!), I've >>noticed that Oystron is almost unplayable, because the player is always >>killed by the pearls flying in the 8th row (counting from the top). Please >>do something..! :-) >I was wondering, the column of dots down the middle of the screen is also >missing. What are they? Players? Any chance I could see the code that >generates the lines with the dots in them? They're Missile 1. Here's the part of the kernel that takes care of them. (it's from release 2.8.5 as I haven't the latest here, but it shouldn't have changed) Sorry, you'll have to do the cycle-counting by yourself, as I was too lazy to do it when I wrote that code.. :-) > STA WSYNC > >; ----------------------- > > STA HMOVE <--- we were positioning P1 in the previous scanline > LDA #%00001100 <----- two copies wide and a decent color, in the same byte :-) > > STA NUSIZ1 > STA COLUP1 > > LDA TEMP+5 <-------- TEMP+5 is always 0 in the first row, we don't want the dots there > STA ENAM1 <------- turns on the dots > > LDA LINESTATUS,Y > BPL VVV > TXA ;0 >VVV: > AND #%10111111 > TAX > ASL > adc ANIMAT > TAY > LDA GRPOIN,Y > STA GRPPNT > > LDA NMYCOLOR,X > STA TEMP > STA COLUP1 ;* <--- I bet we've already drawn the 2nd copy of M1 > > LDX #0 > STX CXCLR ; X=0 > > LDY GRPCOUNT > LDA NUSIZE,Y > STA NUSIZ1 <---- for P1 in the next scanline > > STX ENAM1 <-------- turns off the dots before it's too late > STA WSYNC > >; ----------------------- > LDX PLOFF > P. -- Stella list is Administered by krishna@xxxxxxxxxxxx <Glenn Saunders> Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/stella.html +-shameless plugs-------------------------------------------------------+ | Stella documentary at http://www.primenet.com/~krishna | | Nick's VCS links via http://www.primenet.com/~nickb/atariprg.htm | | Write the best game, win framed autographs of famous Atari alumni!! | +-----------------------------------------------------------------------+
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Re: [stella] Z26 vs. Oystron, John Saeger | Thread | Re: [stella] Z26 vs. Oystron, John Saeger |
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