International Superstar Soccer Deluxe DMA issue

fox68k · Post by **fox68k** » Wed Apr 01, 2009 2:21 pm

Hi All,

I am new to this forum and first of all i would like to thank everyone actively involved in this. It is very nice to have someone else out there to learn.

I am working on a Genesis emulator and at the moment i am trying to figure out what is going on in this game. At the very beginning, i can see this situation:

- DMA is in operation.
- The DMA lasts for more than one scanline, thus forcing me to update clocking in the forthcoming processing.
- After one of the scanline processing, the m68k runs way too far ahead the required clocking (about 400 clocks, which is quite weird, i did not get into it yet).
- In the next scanline, the DMA takes only some clocks for data transfer, and that finally makes game to not work properly as far as i can see.

I wonder if i have to carry on with the extra clocks executed in a scanline for the next scanline.

Any thoughts?

Thank you.

Christuserloeser · Post by **Christuserloeser** » Sun Apr 12, 2009 6:57 am

Nice to see you around fox68k! Welcome to spritesmind!

- Let's hope someone can help you with your question...

fox68k · Post by **fox68k** » Thu Apr 23, 2009 2:09 pm

I am trying to understand the events involved. I cannot get them to work as expected. This particular game seems to require an accurate event handling, and that is why i posted.
There are nice threads explaining some of this stuff, though.