Re: Re: [stella] StellaX PAL detection

Subject: Re: Re: [stella] StellaX PAL detection
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Wed, 30 Jan 2002 16:31:35 +0100
Well, the/my problem is, that in '', as well as in 'defprops.def'
are _no_ "Display.Format" entries, so every game must default
to NTSC. But I don't see the point where that is changed later. Maybe
all of that stuff is obsolete, and I'm totally on the wrong spot here?

You should get the latest version of from Voch's homepage.
It contains "Display.Format" entries for those games that he has
identified as PAL games. The default values for those keys that need
to be set, can be found in the console.cxx file. The values from the file get loaded in the UI code for the system that you use.

Actually I'm not creating an entry for my game, but porting
that thing to DirectX 8 :-) That MD5 stuff will be the first thing I'll
try to get rid off, when I understand more of what I'm doing...
I'm attempting to share the CRCs from Z26 instead, in order
to have the auto-detection always uptodate.

The code for the Windows version, which I think uses DirectX is
inlcuded in the sourcefore repository now, so you might want to
check that out. And even if you don't want to join the Stella
development team, you still might want to subscribe to it's
mailing lists, since that's probably a better place to ask these
questions than here.

Actually Stella and z26 aren't that different when it comes to
detecting games. The only difference is that z26 has the checksums
hardcoded into the executable, while Stella also allows them
to come from a seperate file. And that file is also kept up to date
by Voch, so there isn't much of an advantage for z26.

The only thing we do is that we try to autodetect the TV type.
But for that we only check the number of scanlines during the
first couple of frames. If the game does a stable line number
of more than 285 lines or so, we assume that the game is meant
to be PAL. But something like that could probably be added to
Stella too quite easyly.

BTW: Could you imagine something like a class, that would
load and identify a BIN and holding all it's information. That
class could be the same in StellaX and Z26.

z26 is compiled with MASM and Turbo C, so C++ classes wouldn't
fit in. But we already have a function that does most of the
identification with the checksums. It's in carts.c and the CRC
tables are in ct.c.

And what about handling SC games with that object?

What about it? ;-)
There are no differences between SC binaries and other games
in that respect. SC games are always a multiple of 8448 bytes,
which can be used to identify them. The only problem that
z26 has, is that it is compiled for a 16-bit memory mode, so
that loading large binaries and calculating checksums for them
is a bit tricky.

Besides it'd be good for my emulator, because I never again have
to care about uptodating the identification  :-)

Oh come on, teasing us like that isn't fair. Now you have
to tell us why you want to modify the emulator and what's
going to be so special about your program. ;-)

Ciao, Eckhard Stolberg

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