32MB RAM upgrade

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yzb
shadow
Posts: 5

Re: 32MB RAM upgrade

Post#51 » Fri Oct 16, 2020 9:17 pm

tsowell wrote:
yzb wrote:Because my friend is very interested in this project, he made a set of 32M version of dreamcast, he showed me to study kof98 and see if it can adapt to the 32M version of the game, so this version was born


Hi yzb, thanks for sharing this. I'm really excited to try it out, but I need to put together another 32MB Dreamcast first. Once I finish a couple of other projects...

I'd love to hear more about the changes you had to make to get this working. And do you think your methods would work on other games, at least other KoF versions?



The hardware implantation is adapted from your introduction article
https://blog.ldtlb.com/2020/06/21/dream ... grade.html

Bios tested, jc's 32M bios cannot be flashed on the va1 motherboard. I don't know why, it will automatically restart, so jc's 32 bios can only be flashed on the va0 motherboard


Regarding the game, it cannot be a wince game, other games should be able to use this method. However, the source code of the game has to be modified a lot ASM, so it takes a lot of time :|

In addition, I personally think that dc is already very fast in reading data, and many games do not need to use 32M memory (with gdemu can reach the limit)


Because my friend likes kof98 and changed the 32M dreamcast, so I studied this game

Regarding this 32M kof98, I will add another explanation, because at the beginning, because 16M files are pre-read into the memory, the reading time of 15-20 seconds will be black at the beginning (gdemu uses 5 seconds)
In addition, I don’t know if it’s a bios problem or other problems. It will stop working when playing sfd cg, so I skipped this paragraph in the game and went directly to the title screen of the game.

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Ian Micheal
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Re: 32MB RAM upgrade

Post#52 » Sat Oct 17, 2020 12:10 am

SFD encoder memory is set for 16 mb in games so videos will mess up You have to hack that change the memory allocation

yzb
shadow
Posts: 5

Re: 32MB RAM upgrade

Post#53 » Sat Oct 17, 2020 6:11 am

Ian Micheal wrote:SFD encoder memory is set for 16 mb in games so videos will mess up You have to hack that change the memory allocation



SFD encoder memory is set for 16 mb in games.

Isn't this set in bios?
Is it set in the game's 1st main program?

Sorry I didn't find the relevant code. :|
Can you give me an example?
Or is there a source code for this?

Alexsun
shadow
Posts: 6

Re: 32MB RAM upgrade

Post#54 » Sat Oct 17, 2020 12:00 pm

Thanks for this -- pretty cool stuff.

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