Greetings all.
I am in the process of developing a 6502 game library that can target the C64 and the NES (although still requiring different graphics source files). Eventually, I'd like it to target the Apple II, Atari 800, and the Atari 2600.
As you can imagine, handling each system's differences in a uniform way (where the application code is mostly platform agnostic) is the most difficult part of my goal.
I finally have a firm grasp of the most basic memory configuration for an NES ROM (including the way CHR-ROM's are appended to the end of the binaries).
My biggest concern is having to tailor the library to the 16x16 palette attribute table limitation. I stumbled upon some information regarding MMC5 and the ExGrafix mode. To be able to color background graphics per 8x8 character tiles would be ideal for matching the capabilities of the C64.
It seems as though most people who talk about MMC5 on these forums are not interested in the expanded attribute functionality but more of the other things the MMC5 can provide.
I was wondering if anyone can point me to any sample code showing the use of this particular aspect of MMC5. I'm not really interested in the banking properties which may be why my current attempts have been unsuccessful. I wouldn't mind just using my 32KB PRG and 8KB CHR setup.
I am in the process of developing a 6502 game library that can target the C64 and the NES (although still requiring different graphics source files). Eventually, I'd like it to target the Apple II, Atari 800, and the Atari 2600.
As you can imagine, handling each system's differences in a uniform way (where the application code is mostly platform agnostic) is the most difficult part of my goal.
I finally have a firm grasp of the most basic memory configuration for an NES ROM (including the way CHR-ROM's are appended to the end of the binaries).
My biggest concern is having to tailor the library to the 16x16 palette attribute table limitation. I stumbled upon some information regarding MMC5 and the ExGrafix mode. To be able to color background graphics per 8x8 character tiles would be ideal for matching the capabilities of the C64.
It seems as though most people who talk about MMC5 on these forums are not interested in the expanded attribute functionality but more of the other things the MMC5 can provide.
I was wondering if anyone can point me to any sample code showing the use of this particular aspect of MMC5. I'm not really interested in the banking properties which may be why my current attempts have been unsuccessful. I wouldn't mind just using my 32KB PRG and 8KB CHR setup.