CONFIG_ISDN_DRV_PCBIT
  This enables support for the PCBIT ISDN-card.  This card is
  manufactured in Portugal by Octal.  For running this card,
  additional firmware is necessary, which has to be downloaded into
  the card using a utility which is distributed separately.  See
  <file:Documentation/isdn/README> and
  <file:Documentation/isdn/README.pcbit> for more information.

