taglinefilesource code
quarter640drivers/block/cm206.cint quarter, error; 
quarter654drivers/block/cm206.cquarter = (CURRENT->sector+i) % 4; 
quarter659drivers/block/cm206.cquarter*512 + (cd_sec_no-cd->sector_first)*RAW_SECTOR_SIZE;
quarter663drivers/block/cm206.csource =  ((uch *) cd->sector)+16+quarter*512;