Home Page Forums MAME MAME The SNES WIP topic

Quoting 2 posts above that on this topic:


"Ballz decapping" being the SNES DSP-1.

you might find interesting the fact that the bug was introduced by judge and not by me (also because I haven't touched the driver from last fall to last week ) :P

that said, what I broke a couple of weeks ago was Seiken Densetsu 3 player select screen. however, I never spent time to fix it because I was trying to rewrite the BG drawing routines to be more similar to BSNES ones (so that it's easier to debug MESS, being possible to compare the two sources). I will never thank enough byuu for writing such a clear emulator!

at last, today I managed to complete the changes and to re-add most of the features in the rewritten routines. these are the result:

- Seiken Densetsu 3 back in its previous state


- Tokimeki Memorial better than ever (no text yet, but you can see that priorities and resolutions are correct)


- and, as a bonus, an almost working implementation of offset-per-tiles mode


on the negative side, there are a couple of hires issues which results in not 100% perfect hires texts (e.g. in Desert Fighter,

but it only affects text, Suchi Pai works) and in a few of other minor problems (e.g Star screens in the SNES Test ROM do not scroll properly).

since the gain in readability and opt are imho clear improvements, I will commit these changes as a series of patches either later tonight or tomorrow.

stay tuned...

Nice!

This is excellent news!

If this is a success, and we're able to emulate it properly, then we can gain perfect DSP-3 and DSP-4 support just by dumping the PROMs and using them in place of the DSP-1 PROM. That will lower the number of unemulated games to two.

I'm certain we can easily raise $250 or more for each of the remaining DSPs, if we can show the results with the DSP-1B PROM.

And if they are willing to reveal how it was done, we can probably have neviksti take a stab at the other ones.


I'm sure you're talking about some other issue, but hires and scrolling really don't go well together at all. Given the way it works you're guaranteed to have a jittery mess every other frame when scrolling. Makes it very hard to take a good screenshot.

about "scrolling stars", I think the Test Program alternates main & sub screen to give a sort of scrolling effect. my bet is that we fail to properly emulate some addsub corner case, but my first attempt to fix it, failed. I will try again once I've finished a few other things I wanted to clean up.

from the top of your head, can you remember:

* any game which uses OPT actively in easy to spot places, in addition to SNES Test Program (for the Mario screen above)? I know Puzzle Bobble uses Mode 4, but I was not able to find an occurrence of opt valid bit written

* any game which uses pseudo hires?

* any game which uses mosaic in Mode 5/6?

I think my current code still has some problem with the cases above, but I would need some separate test case for each of them, in order to test fixes...

Wow, I'm good at breaking stuff it seems
Looks like Brandish 2 is another test case for the div/mult timing then (if someone ever manages to figure it out).

Why's that? Does the SNES generate even and odd fields differently in hires mode?

AFAIK the Chrono Trigger logo is supposed to animate using OPT - there's a bugzilla on it.

Yeah there are two OPT bugs:
http://bugzilla.mess.org/show_bug.cgi?id=1843
http://bugzilla.mess.org/show_bug.cgi?id=1847
The second one seems to be almost working now.

Current SVN seems to have a problem where vertical scrolling works OK, but horizontal scrolling is chunky (scrolls several pixels at once rather than one at a time). This can easily be seen at various points in the Chrono Trigger intro.

To me it looks something very "simple" like swapped x dots?

I also wonder why the text doesn't appear in Tokimeki Memorial or the nvram bug in Fushigi no Dungeon 2 / Super Drift Out, maybe it's the right time to check the SNES again, mainly because my current MAME alternatives aren't very satisfactory right now ...