Tuesday, September 02, 2003

Spent a while fixing minor PPU bugs, and other errors due to misinterpretation of documentation. The result is that the homebrew ROM that I've been experimenting with now runs! It only draws a simple image, but demonstrates DMA, CGRAM, and BG layers in operation.

Monday, August 18, 2003

The demo that I'm trying to run uses DMA. I've now implemented basic DMA support, although there's no HDMA support yet. I've also emulated the hardware multiply and divide functionality supported by the SNES. The next stage is to actually output some graphics to the screen.

Monday, August 11, 2003

Implemented all the opcodes necessary to run the homebrew ROM. Started work emulating the basics of the PPU (Picture Processing Unit). I'm going to start by emulating BG1 and Tile Based graphics. So far, PPU registers seem to get written to correctly, which is a promising start. The only real obstacle I've come up against is time!

Thursday, August 07, 2003

Have now implemented 30 65c816 Opcodes... almost enough to step through the homebrew ROM that I'm using. There are a few confusing issues (mainly due to limited documentation), but overall I've found the CPU a lot easier to emulate than the Z80.

My friend Peter has offered me a crate of beer once I get StarFox running (probably because he believes I won't). I wasn't planning on emulating the SuperFX CPU, might now I might consider porting some C code in that area...

Thursday, July 31, 2003

Work has started on JSNES. A Java based SNES Emulator. Like my other project, JavaGear, the source code will be released under the GNU GPL license, once I am happy with progress.

So far, I've implemented the following:
  • Basic ROM Loaders (Simple LoROM / HiROM detection)
  • LoROM memory map
  • 12 x 65c816 Opcodes
I'm quite busy at the moment, so this project may never be completed, but it should prove an interesting learning experience.