> You might notice that some scenes show more colors onscreen than contemporaries like the C64 - this is all because of the display list interrupt techniques Crawford talks about, combined with clever overlaying of the player/missile sprite system.

Similar techniques are heavily used on the C64 too. See e.g.

http://studiostyle.sk/dmagic/gallery/gfxmodes.htm

E.g. here's a bunch of IFLI images:

http://c64pixels.com/main.php?g2_view=keyalbum.KeywordAlbum&...

And here's a bunch using sprite layers:

http://c64pixels.com/main.php?g2_view=keyalbum.KeywordAlbum&...

Like for many of these platforms, it's almost impossible to extract graphics from "newer" games or demos accurately without actually running them in a cycle accurate emulator and in many cases you have to capture at least two frames and interpolate...