#define atBASE 0xc000

/* READ registers AT-interface */
volatile _xdat unsigned char atrDATMSB _at(0xC000);	/* MSB register op interface-kaart */
volatile _xdat unsigned char atrALTERN _at(0xC006);
volatile _xdat unsigned char atrDRIVAD _at(0xC007);
volatile _xdat unsigned char atrDATLSB _at(0xC008);
volatile _xdat unsigned char atrERROR  _at(0xC009);
volatile _xdat unsigned char atrSECCNT _at(0xC00A);
volatile _xdat unsigned char atrSECNR  _at(0xC00B);
volatile _xdat unsigned char atrCYLLOW _at(0xC00C);
volatile _xdat unsigned char atrCYLHIG _at(0xC00D);
volatile _xdat unsigned char atrDRHEAD _at(0xC00E);
volatile _xdat unsigned char atrSTATUS _at(0xC00F);

/* WRITE registers AT-interface */
#define atrDEVCTRL atrALTERN
#define atrFEATURE atrERROR 
#define atrCOMMAND atrSTATUS