Tandy 1400LT Service Manual page 295

Instruction Set (1)
- Instruction Code
Phase R/W D, D, D, D, D, D, D, Do Remarks
Read Data
Command W
MT M F SK
0 0
1 1
0 Command codes
W
W
W
W
W
W
W
W
X X X X X HD US, US,
t
C
- - +
Sector ID information prior to command execution. The 4
c
H
- +
bytes are compared against header on floppy disk.
t
R
--+
c
N
-+
t
EOT
--+
c
GPL -+
t
DTL
--+
Excution Data transfer between the FDD and main system
Result R e STO
- +
Status information after command execution
R t ST 1
--+
R i ST2
-+
R t C
*
Sector ID information after command execution
R e
H
R c R
-+
R t N
--+
Note:
(1) In the Instruction Code, X=don't care (usually set to 0).
(2) A,, should be 0 for SET STANDBY, RESET STANDBY, and SOFTWARE RESET commands and 1 for all
other commands.
Instruction Set (2)
- Instruction Code
Phase R/W D, D, D, D, D, D, D, Do
Remarks
Read Deleted Data
Command
W
W
W
W
W
W
W
W
W
MT MF SK 0 1 1 0 0 Command codes
t
C Sector ID information prior to command execution. The 4
c
H
*
bytes are compared against header on floppy disk.
i
R
f
t
N
i
EOT
-+
t
GPL -+
c
DTL
-+
X X X X X HD US, US,
Execution
Data transfer between the FDD and main system
Result R t STO
r
Status information after command execution
R i ST 1
-+
R < ST2
R i C
+
Sector I D information after command execution
R t H
R i R
f
R t N z
Write Data
Command W
W
W
W
W
W
W
W
W
MT M F 0 0 0
1
0
1
Command codes
c
C Sector ID information prior to command execution. The 4
t
H
'
bytes are compared against header on floppy disk.
c
R
f
c
N
-+
i
EOT
c
GPL
-+
i
DTL
r
X X X X X H D US, US,
F-26