PERPENDICULAR MODE
DATA BUS
PHASE
R/W
REMARKS
D7
0
D6 D5 D4 D3 D2
D1
D0
0
Command
W
0
0
0
1
0
0
1
Command Codes
OW
D3 D2 D1 D0
GAP
WGATE
INVALID CODES
DATA BUS
PHASE
R/W
REMARKS
D7 D6 D5 D4 D3 D2 D1 D0
Command
W
----- Invalid Codes -----
Invalid Command Codes
(NoOp - FDC goes into Stand-
by State)
Result
R
------- ST0 -------
ST0 = 80H
LOCK
DATA BUS
PHASE
R/W
REMARKS
D7
LOCK
0
D6 D5
D4
1
D3 D2 D1 D0
Command
Result
W
R
0
0
0
0
0
0
1
0
0
0
0
0
Command Codes
LOCK
SC is returned if the last command that was issued was the Format command. EOT is returned if the last
command was a Read or Write.
Note: These bits are used internally only. They are not reflected in the Drive Select pins. It is the user's
responsibility to maintain correspondence between these bits and the Drive Select pins (DOR).
55
SMSC [ SMSC CORPORATION ]
