You can't -- not directly, at least. The SCREEN 12 is comp[osed out of four
different memory pages, _each_ of which are mapped at memory location
&HA000.

You have to save all four planes independently. This means, that is you
want to use BSAVE/BLOAD (the fastest way) you will always end up with four
different datafiles.

OUT &h3CE, 4
ORIGINAL = INP(&h3CF)
' Get current plane value

FOR plane = 0 to 3
        OUT &h3CE, 4
        OUT &h3CF, plane
        ' Now, memory location &HA000 contains one of the four bitplanes.
        ' You can save this to disk using BSAVE, or use PEEK / PEEK$ to
        ' retrieve the information. I'm not sure about the amount of memory
        ' each of these planes take, though.
NEXT plane

OUT &h3CE, 4
OUT&h3CF, ORIGINAL
' Restore the original plane
--
Marc van den Dikkenberg
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