Archive for October, 2008
Bring out the girls and let’s have a mud fight
Wednesday, October 8th, 2008Ok,here’s the story: the D2 register wasn’t consistent so I had to write a new ASM m68k function for this issue.In about two hours to write + debug boring opcodes in machine language I’ve done and in a uncalculated time (in between 1 and 5 minutes I think) I’ve hooked up a sort of DMA/protection thing on which the game accesses hoping that nobody will be so smart to notice that 😉
Now I just need to clean-up the whole driver and it’s ready for the submission.
Next to come only on this radio station: write debug code for Alien Command,to let it finally boot.
When you hear hoofbeats, think horses, not zebras
Monday, October 6th, 2008Found the problem with it,I tried every possible thing on Earth with it and finally the simplest solution pops up: it seems that the protection jump at $f03c0 a.k.a. the palette ram sub-routine is called with the wrong vector.Differences between this call and all the others is that the D2 register is not equal to zero but is equal to 0x0b00000.My 0,50 € guess is that the programmers added this extra “feature” to protect the most interesting thing of this game. 😛
Now I need to check the other two girls and if there’s consistency I have to add this to the sub-routine…
Where the grass is green and the girls are pretty
Sunday, October 5th, 2008Swinging swords like Shinobi
Thursday, October 2nd, 2008As I’ve expected previously,this game simply uses different addresses for the video ram and two planes instead of four.It appears to be an earliest revision than the other games of this hardware,namely:
urashima -> daireika/mjzoomin -> kakumei/kakumei2 -> suchipi
Needless to say,the game now “somewhat” works.Still to do: fix/find the tile banking (as you can see in snap 4) and double check the scrolling registers.