Fdc Commands - NEC Advanced Personal Computer System Reference Manual

Controller PCB
Table 3-9 FDC Commands
READ/ DATA BUS
PHASE WRITE D7 D6
D5 D4 D3 D2 DI DO REMARKS
READ DATA
Command W
MT MF SK 0 0 I I 0 Command Codes
W X X
X X X HD USI
usa
W
C
Sector ID information
W
H prior to Command
W
R execution
W
N
W
EOT
W
GPL
W
DTL
Execution
Data transfer between
the FDD and main
system
Result R
STO Status information after
R
STI Command execution
R ST2
R C Sector ID information
R
H
after Command
R
R
execution
R N
READ DELETED DATA
Command W
MT MF SK 0 I I 0 0 Command Codes
W X X X X X HD USI
usa
W
C Sector ID information
W
H prior to Command
W
R execution
W
N
W
EOT
W
GPL
W DTL
Execution
Data transfer between
the FDD and main
system
Result R
STO Status information after
R STI command execution
R ST2
R
C Sector ID information
R H after command
R R execution
R N
X
=
Don't care.
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