Re: [stella] Thomas Jentzsch's PAL -> NTSC Conversions

Subject: Re: [stella] Thomas Jentzsch's PAL -> NTSC Conversions
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Mon, 4 Feb 2002 15:32:06 +0100
> While Thomas sent us 21 different NTSC images, I've only put 18 online so
> far.  I'd first like to confirm that two of them aren't, in fact, NTSC
> binaries (Air Raid and Great Escape).  And we need to dump an NTSC
> as the ROM on our site appears to be PAL.

Polaris is a difficult game to dump. I don't think it's possible with
the 7800 based cartridge reader. The same goes for Espial, which also
is only floating around the net as a PAL ROM.

> Maybe you guys can help me confirm or deny if the existing Air Raid and
> Great Escape binaries are PAL or NTSC.  Air Raid uses 290 lines and Great
> Escape uses 288 lines.  At what point is a game considered PAL?  I
> be surprised if Great Escape is PAL, since it's easier to find outside the
> US.  But as far as I know, Air Raid wasn't distributed outside the US, so
> PAL version of it would seem a bit unusual to me.  Here are the binaries
> both of these games:

Games in the 280 line range are a bit difficult to judge, as they
could be for either format. But I think the two binaries above are
from the NTSC carts. Great Escape is from a Hong Kong based company
called BOMB / OnBase. Therefore I think the original version was
for PAL. If you look at the radar screen with a PAL palette, you'll
see that it is green in normal mode and red when the mothership appears.
But OnBase doesn't seem to have fixed the colours for the NTSC versions
of their games. I have a PAL cart of Z-Tack, which does the usual 312
lines. The NTSC ROM of this game from the net uses the same colour
values as my PAL version. So I think the Great Escape ROM that you have
is either a badly done NTSC conversion, or OnBase went on to create
hybrid versions of their games that would work on both TV standards.
We could only be sure, if we were able to dump the ROM of the PAL
version of Great Escape.

As for Air Raid, the colours in that ROM sure look as if they are
meant for NTSC. The sky is blue (purple with a PAL palette) and
the Men-A-Vision logo is yellow, which is a colour that would
show as grey in PAL. So I think this was originally written for
the NTSC market. Greg Troutman's final version of "This Palanet
Sucks" also accidentally did more than 280 scanlines, due to a
small bug. It took quite a while before someone who had bought
the cartridge complained about it, so that Greg could fix it.
Therefore I think a NTSC version of Air Raid with 290 lines
might be possible.

ciao, Eckhard Stolberg

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