NEOchrome file format

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NEOchrome       *.NEO
1 word          flag word [always 0]
1 word          resolution [0 = low res, 1 = medium res, 2 = high res]
16 words        palette
12 bytes        filename [usually "        .   "]
1 word          color animation limits.  High bit (bit 15) set if color
                animation data is valid.  Low byte contains color animation
                limits (4 most significant bits are left/lower limit,
                4 least significant bits are right/upper limit).
1 word          color animation speed and direction.  High bit (bit 15) set
                if animation is on.  Low order byte is # vblanks per step.
                If negative, scroll is left (decreasing).  Number of vblanks
                between cycles is |x| - 1
1 word          # of color steps (as defined in previous word) to display
                picture before going to the next.  (For use in slide shows)
1 word          image X offset [unused, always 0]
1 word          image Y offset [unused, always 0]
1 word          image width [unused, always 320]
1 word          image height [unused, always 200]
33 words        reserved for future expansion
16000 words     picture data (screen memory)
32128 bytes     total

NEOchrome virtual canvas:
These files have the same file extension, but contain an image that is 640x400 in 16
colors. They are created with a special version of NEOchrome (v0.9h) included on the
Atari 7800 game console devkit disk. This special version lets the user scroll around
a much larger virtual canvas.

Differences from standard NEO files:
flag word [0xBABE]
image width [640]
image height [400]
picture data: 64000 words
total file size: 128128 bytes

Back to ST Picture Formats