MAMEWorld Forums - News - Re: Haze: DS5002FP Dumping

> > > This reminds me of Raiden II and long termed "impossible to emulate" situation.
> >
> > Except while Raiden II has gradually been made playable due to Kale's hard work, I
> > don't think anyone knows with 100% certainty whether the Seibu COP emulation is
> 100%
> > correct or not. There could be any number of subtle issues in rarely-used code
> paths.
> > The worst thing is that by all accounts, the Seibu COP isn't a microcontroller and
> > doesn't appear to have internal ROM, it's just a huge gate array which could be
> doing
> > basically anything.
> >
> > It's a testament to Kale's tenacity and intelligence that Raiden II is as playable
> as
> > it is, but short of someone doing comprehensive trojaning of the results that the
> > Seibu COP sends back for various commands, I think the "impossible" label for
> Raiden
> > II and associated games is still rather apt.
> >
> > To be honest, I would consider the new DS5002FP dumping effort to be in the same
> > realm of not-quite-100% as Seibu COP, since I seem to recall Haze pointing out that
> > none of these games do any checksums on the contents of the DS5002FP's RAM - so the
> > only way to determine whether the dump is good or not is to simply try it in MAME
> and
> > see whether or not it fails to work correctly. Then there's the additional layer of
> > uncertainty of whether or not any misbehavior might be due to inaccuracies in
> MAME's
> > 8051 core, as opposed to inaccuracies in the dumps.
> >
> > Nonetheless, it's still an absolutely amazing accomplishment, and both Peter and
> > Morten deserve all of our congratulations. But make no mistake, this is hardly the
> > final chapter in this particular story. Rather than closing the book, it opens new
> > doors to explore.
>
> Raiden 2 in the end was mostly OG, although we managed to correlate a lot of what was
> found by Kale for the other games so implementations are mostly shared, various bugs
> were fixed along the way by doing this.
>
> Seibu COP is something that has been worked on by a lot of people over the years tho,
> there are still contributions I made to that (eg. the finer details of some of the
> collisions based on extensive feedback from Raiden 2 players who knew exactly how big
> and where the hitboxes should be for each power-up level of ship as you can't pass
> through certain patterns fully-powered as you have a hitbox that is slightly bigger
> too)
>
> Unfortunately, no, Gaelco didn't checksum any of this, and the chips are going bad,
> so until we've got 2 of each game secured it's actually a bit of a risk releasing
> anybody because we're already seeing people jump on the 'going to buy up bad boards
> and reprogram them' bandwagon (and obviously a reprogrammed board doesn't help verify
> at all)
>
> The DS5002FP even has a checksum function in hardware where you can program a
> checksum into it, have the bootstrap check it, and wipe sram / put it back in
> programming mode if the data becomes corrupt, however, it doesn't appear to be used
> here, hence why instead we're seeing games where some of the ram bits have gone
> flakey.

Now that the World Rally 2 MCU is dumped, is WR2 now fully playable, although your commit doesn't explicitly state it?

https://github.com/mamedev/mame/commit/199ce7d06da149804c6ed998bf39206f69885197

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