SPX_BG_MASK
cur_fg = (attr & SPX_BG_MASK) >> 4;
cur_bg = (attr & SPX_BG_MASK) >> 4;
dot_bg = (attr & SPX_BG_MASK) >> 4;
dot_fg = (attr & SPX_BG_MASK) >> 4;
(fillattr & SPX_BG_MASK) >> 4);
(fillattr & SPX_BG_MASK) >> 4);
myattr = (fg & SPX_FG_MASK) | ((bg << 4) & SPX_BG_MASK);