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SubjectRe: CPU cycles in V/HBLANK  
Posted by<_Hyde_>
Posted on6/17/04 10:52 AM
From IP66.53.54.64  



I thought I'd post something here based on my experience. During the scanline emulation process, you should execute the CPU core for 84/85 cycles. This amount corresponds to the number of CPU cycles it takes the PPU to render 256 pixels. Once this is done, you should update the vertical/horizontal scrolling counters (Loopy_V and Loopy_T). After that, the core should execute 29 other cycles (corresponding to the HBlank period) and then update Loopy_V with Loopy_T (Loopy_V = Loopy _T). This scheme has worked quite well for me: games like Battletoads, Radracer, and Bigfoot run without glitches.

hydesprojects.cjb.net

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Entire Thread
Subject  Posted byPosted On
*CPU cycles in V/HBLANK  Anonymous6/16/04 5:23 PM
.*Re: CPU cycles in V/HBLANK  Disch6/16/04 5:33 PM
..*Re: CPU cycles in V/HBLANK  Muchaserres6/17/04 08:47 AM
....Re: CPU cycles in V/HBLANK  <_Hyde_>6/17/04 10:52 AM
....*Re: CPU cycles in V/HBLANK  Zipplet6/23/04 04:45 AM
.....*Re: CPU cycles in V/HBLANK  <_Hyde_>6/23/04 10:33 AM
......*Re: CPU cycles in V/HBLANK  tepples6/23/04 5:52 PM
.......*Re: CPU cycles in V/HBLANK  <_Hyde_>6/23/04 9:39 PM
........*Re: CPU cycles in V/HBLANK  Zipplet6/24/04 1:39 PM
........*Re: CPU cycles in V/HBLANK  tepples6/24/04 1:30 PM
........*Re: CPU cycles in V/HBLANK  <_Hyde_>6/23/04 9:58 PM
...*Re: CPU cycles in V/HBLANK  Memblers6/17/04 09:37 AM
...*Re: CPU cycles in V/HBLANK  Disch6/17/04 09:36 AM
....*Re: CPU cycles in V/HBLANK  Anonymous6/18/04 3:29 PM
..*forgot about VBlank =P  Disch6/16/04 5:41 PM
...*Re: forgot about VBlank =P  Anonymous6/16/04 8:56 PM
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