I realize that 263 lines is only a field, not a frame. But they were
describing this as a doubling of the 2600 line qualities.
Do they really mean that the Supercharger used progressive scan, or was
the 2600 not even doing interlaced?
Most game systems fool the TV into doing a progressive scan mode. You won't
see interlace flicker compared to normal broadcast television.
The 2600 generates its display one scanline at a time. Its registers only
have enough RAM to store half the playfield and the sprite graphics and
positions for that one scanline. You need to write routines in ROM to
adjust these RAM locations as the kernel draws. But ROM is not dynamic, so
how do you create playfields that have a lot of animation in them?? Using
what little system RAM is left, you can create non-reflective playfields you
can "draw" on (ala Surround). How that exactly works, I'm not sure. You
can also create a fixed playfield and have a bitmap representing the state
of things like the power pellets in Pac Man, whether they are on or off, but
that's not exactly a bitmap display per se. With the supercharger, there is
enough memory, however, to represent all the graphics data that will be used
by the kernel for the entire screen within a big block of RAM, so you can
use a general-purpose blitting routine each scanline that has a moving
pointer sliding through this block of RAM and your main loop can merely
change the memory of this "pseudobitmap" at any time and anywhere on the
screen regardless of beam position by writing to RAM. In that way you can
draw entire frames in a more traditional "bitmap" method.
I think this is how Suicide Mission does it, and other Supercharger games
may take advantage of the RAM in similar ways.
Could someone explain in further detail?
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