| SLIM |
2004-12-21 10:51 |
我这星期六为了与SNES同步在调整NTSC时浪费了很多时间。如果你想要知道更多的细节，请看zsnes开发文档，但从本质上说，bsnes现在已经在NTSC同步上非常完美了，但是调速以后就不同步了。
我也重写了HDMA代码等
总之作者将在下个版本支持声音。
原文：
I spent a few hours Saturday messing around with NTSC timing, trying to get something in sync with the SNES. Look on the zsnes development board if you want more specifics on this, but essentially, bsnes is now perfectly in sync with NTSC, excepting that there isn't any speed throttling. There may be periods where the SNES is frozen to allow NTSC to catch up that I don't have in my emulator yet, however. Basically, I use 1365 cycles per scanline now. I get that number from:
(1365 * 525 * (30 / 1.001)) = ((315 / 88) * 1000000) * 6 = SNES clock speed
I also rewrote the HDMA code, which really sucked. Thanks to a document from anomie, I was able to cut the size of the routines down by probably five times or so what they were before. I also added all 8 transfer modes. I also overhauled the H/DMA timing. DMA will now just lock the processor and transfer byte by byte, updating the screen as it goes along. This will allow me to stop allowing register writes if the DMA transfer is so long that it exceeds h/vblank. I also added timing to HDMA initialization and per line, along with direct and indirect transfer overhead. A huge thanks to anomie again, It'd have probably taken me a year to figure all of his notes out on that on my own. I also now allow $43x8/9/a to be read from and written to, although I somehow doubt that I have that working properly.
With these fixes, Final Fantasy V's opening works much better. The last problem is that the actual title still doesn't mirror upside down below the top one. But the mode7 part with the credits runs great now.
It's taking forever to get the spc700 done, because I really don't like writing CPU cores. I don't want to release a new version until I have it working, though. The next release won't have sound: but it will support the sound processor. It's kind of a first step along the way. |
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