November 7th, 2006, 14:44
The Show Must Go On!
bsnes WIP Report
A new bsnes work in progress report has been posted today.
I rewrote a lot of the cartridge file processing code to support the Bandai Sufami Turbo. All thirteen games are playable, and all are dualable in any combination. There are a few technical limitations such as SRAM always mapping as 128kbit in all games and cheat files only loading from the first cartridge (ROM cheats being unreliable when you switch which slot a given game is plugged into anyway), however since all games are fully playable, and this technically has little to do with the SNES, I am very satisfied with the results. The technical limitations are mostly related to the abstraction of the bus controlling PCB-based memory mapping (the MMC obviously exists in the cartridge, whereas the memory mapper is the most logical location to decode addresses in an emulator), thusly expecting single linear blocks for ROM and RAM, and the Sufami Turbo requiring two separate ROMs and SRAM regions. While it's possible to get around this, I've decided the additional work and overcomplication of one of the most vital parts of emulation is not worth the effort for only thirteen games. Hopefully everyone will agree that my Sufami Turbo implementation is more than sufficient.
I also fixed a tiny glitch with IRQs affecting Final Fantasy: Mystic Quest (E) (yes, that's right, I'm calling the European version Final Fantasy, take that Square), which may or may not have affected the last public release. I'm currently working on an IRQ fix that will correct both R-Type III and Robocop at the same time, but every fix I come up with breaks one of my test ROMs, fun.
Lastly, a fix for Michael Jordan: Chaos in the Windy City, single writes to BGnVOFS registers appear to act differently than single writes to BGnHOFS registers. Check the ZSNES forum if you want to read my long-winded technical explanation of this. The maps now ... do whatever it is they do ... correctly.
Head on over to bsnes' WIP page to check out the screenshots and previous work in progress reports.
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