Another WIP I had nothing to do with, but am happy to show it anyway since it’s one more PSX-hardware game that at least boots (I think the final holdout is NBA Jam Extreme. It tasks me…)

Anyway, reverse-engineering by Olivier Galibert based on drunken long-ago work by Duddie with MAME implementation by smf gets you this:

Before everyone hyperventilates, the game is 100% unplayable – only parts of the characters appear, the camera moves seemingly at random, and lots of other weird screwups occur. In other words, there’s still more protection.

Since variety is the spice of life, smf has a few different shots of his own to taunt the Guru.

Sometimes through circumstances we *do* get to see how things might have turned out.

(Err, that sounded kinda emo, didn’t it? Hang on, this post is *not* an existential crisis, I promise).

Suppose the Dreamcast had hung on and perhaps even knocked out the Xbox or Gamecube. What kinds of crazy hidden powers would developers be pulling out of it now? Look no further than the latest Naomi games. Yeah, Naomi has more RAM, but the ports released during the DC’s lifetime didn’t exactly show huge degredation.

Anyway, one of the great untapped resources in the DC was it’s AICA audio chip – in every respect it’s roughly 2-3 times more powerful than the Saturn and Model 2/3’s already formidable SCSP, but Dreamcast games tended to just stream their music and ignore the available synthesis power. On arcade platforms it’s much harder to justify streaming so Naomi games tend to let the AICA really come out and play.

So what all this is leading up to is that Warashi has posted an OST MP3 from their gorgeous new Naomi shmup Trigger Heart Execelica. You can have a listen right here and think about what might have been. (Even if you don’t like the actual musical style, which is distinctly 80s synthpoppy, just listen to the quality of the instruments).

Thanks to Sixtoe @ System16 for the heads-up.

Booya!

I found the remaining M377xx core bug that was preventing System 22 games from using the dumped C74 BIOS. It’s actually a difference from the 65C816: for anyone who’s done any SNES hacking, you might find this interesting. Or not.

Take this assembly program, which is the same on both processors (except the 7700 doesn’t need the first two instructions – it has no 6502 emulation mode):
CLC
XCE ; make sure we’re in native mode – 65816 only
REP #$30 ; all registers to 16 bits
LDA #$0123
LDX #$4567
LDY #$89AB
SEP #$30 ; all registers to 8 bits
REP #$30 ; back to 16 again

Now, what are the 16-bit values of A, X, and Y at that point? On a real 65C816 (tested on an Apple IIgs) A is 0123, X is 0067, and Y is 00AB. On the M377xx (I can’t test on one, but there’s a routine at C881 in the C74 BIOS that makes this behavior extremely clear) A is 0123, X is 4567, and Y is 89AB.

The upshot is that with this and some other fixes, the System 22 games (including Ace Driver!) now play music using their own real correct BIOSes. No more BAD DUMP and PR1DATA.8K tomfoolery.