HP 7957A Hardware Manual page 36

Theory Of Operation
7957/7958
FIXED SECTOR N IDENTICAL SECTORS
__
------------------------------)l~------------------------------------_
(
,
-INDETlJ
Lr
SECTOR
.... 1 ...
,2 ....
*I ..
~~Y-T-E-S-
ADDRESS AREA - - - -.... . - - - - - - - DA T A AREA - - - - -....
~~
BYTES:
BYTES;
~Intersector
Gap
~PLO
Sync
~Byte
Sync Pattern
GAddress Fie I d
I}]CY I i nder MSB
[I]CY I i nder LSB
~Head
~sector
~Flag
Status
~Pad
Byte
~Address
Check Bytes
~Address
Pad
~Write
Splice
BPLO Sync Bytes
~Byte
Sync Pattern
~Data
Field
~Data
Check Bytes
~Data
Pad Bytes
11
BYTE DATA
SYNC DATA CHECK
PATT FIELD BYTES
256 6
D..ATA
PAD
00
2
ISG
00
, 4 BYTES MINIMUM
- bytes used for sector separation
- 11 bytes for phase-and frequency-synchronization
with data bits recorded on media
- 1 byte indicates beginning of address
fie I din for ma t ion
- 6 bytes
- 1 byte cyl inder most significant bit
- 1 byte cylinder least significant bit
- 1 byte for head address
- 1 byte for sector address
- 1 byte for status byte
- Loaded With FF
- 2 bytes for verifying address field when address
field is read
- 2 bytes for field address check codes for
file integrity
- 1 byte allows internal circuits sufticent
time to ensure dato recovery.
Controller sends 00 at this time
- 11 bytes required when reading to allow circuits to
became phose and frequency synchronized with data
bits on media. Controller sends 00 at this time.
- 1 byte to establ ish byte synchronization and indicates
beginning of dolo field
- 256 bytes of dota
- 6 bytes for error correction code (ECC) information
- 2 bytes to ensure proper recording and recovery
S7i57A02
of lost bits of doto check bytes.
Controller sends 00 at this time.
Figure -. ector Format
3-4