121 #define MOTOR_ON	(ciab.prb &= ~DSKMOTOR)
122 #define MOTOR_OFF	(ciab.prb |= DSKMOTOR)
123 #define SELECT(mask)    (ciab.prb &= ~mask)
124 #define DESELECT(mask)  (ciab.prb |= mask)
277 	unsigned char prb = ~0;  in fd_select()  local
289 		prb &= ~DSKSIDE;  in fd_select()
291 		prb &= ~DSKMOTOR;  in fd_select()
292 	ciab.prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));  in fd_select()
293 	ciab.prb = prb;  in fd_select()
294 	prb &= ~SELMASK(drive);  in fd_select()
295 	ciab.prb = prb;  in fd_select()
301 	unsigned char prb;  in fd_deselect()  local
318 	prb = ciab.prb;  in fd_deselect()
319 	prb |= (SELMASK(0)|SELMASK(1)|SELMASK(2)|SELMASK(3));  in fd_deselect()
320 	ciab.prb = prb;  in fd_deselect()
398 	unsigned char prb;  in fd_calibrate()  local
406 	prb = ciab.prb;  in fd_calibrate()
407 	prb |= DSKSIDE;  in fd_calibrate()
408 	prb &= ~DSKDIREC;  in fd_calibrate()
409 	ciab.prb = prb;  in fd_calibrate()
413 		prb &= ~DSKSTEP;  in fd_calibrate()
414 		ciab.prb = prb;  in fd_calibrate()
415 		prb |= DSKSTEP;  in fd_calibrate()
417 		ciab.prb = prb;  in fd_calibrate()
421 	prb |= DSKDIREC;  in fd_calibrate()
424 		prb &= ~DSKSTEP;  in fd_calibrate()
425 		ciab.prb = prb;  in fd_calibrate()
426 		prb |= DSKSTEP;  in fd_calibrate()
428 		ciab.prb = prb;  in fd_calibrate()
450 	unsigned char prb;  in fd_seek()  local
473 	prb = ciab.prb;  in fd_seek()
474 	prb |= DSKSIDE | DSKDIREC;  in fd_seek()
476 		prb &= ~DSKSIDE;  in fd_seek()
479 		prb &= ~DSKDIREC;  in fd_seek()
481 	ciab.prb = prb;  in fd_seek()
491 		prb &= ~DSKSTEP;  in fd_seek()
492 		ciab.prb = prb;  in fd_seek()
493 		prb |= DSKSTEP;  in fd_seek()
495 		ciab.prb = prb;  in fd_seek()