$CPU 8086          ' make compatible with XT systems
$LIB ALL OFF       ' turn off all PowerBASIC libraries
$ERROR ALL OFF     ' turn off all PowerBASIC error checking
$OPTIMIZE SIZE     ' optimize for smaller code
$COMPILE UNIT      ' compile to a UNIT (.PBU)

DEFINT A-Z         ' Required for all numeric functions, forces PB to not
                   ' include floating point in UNIT (makes it smaller)
'/*------------------------------------------------------------------*/
$CODE SEG "MLIB1"
'/*------------------------------------------------------------------*/
' CALCBYTE ATTR,FCOLOR,BCOLOR
'     Returns the forground and background color numbers calculated
'     from ATTR.
'     EXAMPLE:  CALCBYTE 112,FCOLOR,BCOLOR
'
'     See MKATTR, RATTR
'/*------------------------------------------------------------------*/
SUB CALCBYTE(ATTR%,FCOLOR%,BCOLOR%) PUBLIC
      XN = ATTR%
      CF = (XN MOD 16)
      CB = (((XN - CF) / 16) MOD 128)
      IF CB > 7 THEN
        CB = CB - 8
        CF = CF + 16
      END IF
      FCOLOR% = CF
      BCOLOR% = CB
END SUB