
71
Table 31 - Verify Command Result Phase Table
MT
EC
SC/EOT VALUE
TERMINATION RESULT
0
SC = DTL
EOT
≤ # Sectors Per Side
Success Termination
Result Phase Valid
0
SC = DTL
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
0
1
SC
≤ # Sectors Remaining AND
EOT
≤ # Sectors Per Side
Successful Termination
Result Phase Valid
0
1
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
1
0
SC = DTL
EOT
≤ # Sectors Per Side
Successful Termination
Result Phase Valid
1
0
SC = DTL
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
1
SC
≤ # Sectors Remaining AND
EOT
≤ # Sectors Per Side
Successful Termination
Result Phase Valid
1
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
Unsuccessful Termination
Result Phase Invalid
NOTE:
If MT is set to "1" and the SC value is greater than the number of remaining formatted
sectors on Side 0, verifying will continue on Side 1 of the disk.
Format A Track
The Format command allows an entire track to be formatted.
After a pulse from the IDX pin is
detected, the FDC starts writing data on the disk including gaps, address marks, ID fields, and data
fields per the IBM System 34 or 3740 format (MFM or FM respectively). The particular values that
will be written to the gap and data field are controlled by the values programmed into N, SC, GPL,
and D which are specified by the host during the command phase. The data field of the sector is
filled with the data byte specified by D. The ID field for each sector is supplied by the host; that is,
four data bytes per sector are needed by the FDC for C, H, R, and N (cylinder, head, sector number
and sector size respectively).
After formatting each sector, the host must send new values for C, H, R and N to the FDC for the
next sector on the track. The R value (sector number) is the only value that must be changed by the
host after each sector is formatted. This allows the disk to be formatted with nonsequential sector
addresses (interleaving). This incrementing and formatting continues for the whole track until the
FDC encounters a pulse on the IDX pin again and it terminates the command.
Table 33 contains typical values for gap fields which are dependent upon the size of the sector and
the number of sectors on each track. Actual values can vary due to drive electronics.