FDC37C93XAPM View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
Manufacturer
FDC37C93XAPM
SMSC -> Microchip
FDC37C93XAPM Datasheet PDF : 280 Pages
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Format A Track
After formatting each sector, the host must send
new values for C, H, R and N to the FDC for the
The Format command allows an entire track to next sector on the track. The R value (sector
be formatted. After a pulse from the IDX pin is number) is the only value that must be changed
detected, the FDC starts writing data on the disk by the host after each sector is formatted. This
including gaps, address marks, ID fields, and allows the disk to be formatted with
data fields per the IBM System 34 or 3740 nonsequential sector addresses (interleaving).
format (MFM or FM respectively). The particular This incrementing and formatting continues for
values that will be written to the gap and data the whole track until the FDC encounters a pulse
field are controlled by the values programmed on the IDX pin again and it terminates the
into N, SC, GPL, and D which are specified by command.
the host during the command phase. The data
field of the sector is filled with the data byte Table 27 contains typical values for gap fields
specified by D. The ID field for each sector is which are dependent upon the size of the sector
supplied by the host; that is, four data bytes per and the number of sectors on each track.
sector are needed by the FDC for C, H, R, and Actual values can vary due to drive electronics.
N (cylinder, head, sector number and sector size
respectively).
FORMAT FIELDS
SYSTEM 34 (DOUBLE DENSITY) FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
80x 12x
50x 12x
Y D E O R 22x 12x
DATA R GAP3 GAP 4b
4E
00
4E 00
L
C
C 4E 00
C
3x FC
3x FE
3x FB
C2
A1
A1 F8
SYSTEM 3740 (SINGLE DENSITY) FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
40x
6x
26x 6x
Y D E O R 11x 6x
DATA R GAP3 GAP 4b
FF
00
FF 00
L
C
C FF 00
C
FC
FE
FB or
F8
PERPENDICULAR FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
80x 12x
50x 12x
Y D E O R 41x 12x
DATA R GAP3 GAP 4b
4E
00
4E 00
L
C
C 4E 00
C
3x FC
3x FE
3x FB
C2
A1
A1 F8
61
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