-`setpci -s 12:3.4 34.l=1,2,3' writes longword 1 to register 34, 2 to register 35
-and 3 to register 35 of device at bus 12, slot 3, function 4.
+`setpci -s 12:3.4 3c.l=1,2,3' writes longword 1 to register 3c, 2 to register 3d
+and 3 to register 3e of device at bus 12, slot 3, function 4.
+.PP
+`setpci -s 13:8.4 40.b=50:d0,04:0c,ff' works on bus 13, device 8, function
+4: turns bit 7 off and bits 6 and 4 on in the byte register 40; turns
+bit 3 off and bit 2 on in the byte register 41; sets byte register
+42 to ff.