detected                  
   }
  NRC_IFBUSY      = $21;    { interface busy, IRET before retrying    
   }
  NRC_TOOMANY     = $22;    { too many commands outstanding, retry lat
er }
  NRC_BRIDGE      = $23;    { ncb_lana_num field invalid              
   }
  NRC_CANOCCR     = $24;    { command completed while cancel occurring
   }
  NRC_CANCEL      = $26;    { command not valid to cancel             
   }
  NRC_DUPENV      = $30;    { name defined by anther local process    
   }
  NRC_ENVNOTDEF   = $34;    { environment undefined. RESET required   
   }
  NRC_OSRESNOTAV  = $35;    { required OS resources exhausted         
   }
  NRC_MAXAPPS     = $36;    { max number of applications exceeded     
   }
  NRC_NOSAPS      = $37;    { no saps available for netbios           
   }
  NRC_NORESOURCES = $38;    { requested resources are not available   
   }
  NRC_INVADDRESS  = $39;    { invalid ncb address or length > segment
   }
  NRC_INVDDID     = $3B;    { invalid NCB DDID                        
   }
  NRC_LOCKFAIL    = $3C;    { lock of user area failed                
   }
  NRC_OPENERR     = $3f;    { NETBIOS not loaded                      
   }
  NRC_SYSTEM      = $40;    { system error&nbs