PCX Files

I''ve got a tech. reference for the PCX file format from ZSoft Corporation, but I''m unclear as to 1) How are Planes organized, 2) How are the colors organized in the palettized modes, and 3) in the later versions, does the colormap at the bottom ALWAYS contain 256 colors? Thanks. fuzzy "Gee Look Ma! Someone''''s Figured Out The Integrate of the Derivative of Pi to the Second Divided by the Golden Ratio!" -My Southern Friend