beautypg.com

2 logical address – FUJITSU MPG3XXXAH User Manual

Page 178

background image

C141-E112-01EN

6 - 7

6.2.2

Logical address

(1)

CHS mode

Logical address assignment starts from physical cylinder (PC) 0, physical head (PH) 0, and
physical sector (PS) 1 and is assigned by calculating the number of sectors per track which is
specified by the INITIALIZE DEVICE PARAMETERS command. The head address is advanced
at the subsequent sector from the last sector of the current physical head address. The first
physical sector of the subsequent physical sector is the consecutive logical sector from the last
sector of the current physical sector.

Figure 6.5 shows an example (assuming there is no track skew).

LS

63

LH2

LH1

LH0

LS

2

LS

1

LS

1

608

607

606

190

189

64

63

62

3

2

23

22

1

1

127

126

Physical sector

Physical sector

ex: Zone 0

Physical parameter
- Physical sector: 1 to 608
Specification of INITIALIZE DEVICE PARAMETERS command
- Logical head: LH=0 to 15
- Logical sector: LS=1 to 63

Physical cylinder 0

Physical head 1

Physical cylinder 0

Physical head 0

LS

63

LS

1

LS

63

LS

1

LS

41

LS

40

LS

39

. .

. .

. .

. .

. .

. .

. .

. .

LS

63

LS

42

LS

1

LS

63

LS

1

LS

63

LS

1

. .

. .

. .

. .

. .

. .

. . . .

. . . . . . . . . . . . . .

. . . . . . . . . . . . . .

LH10

LH9

LH11

LH12

86

148

85

608

607

LH9

Figure 6.5

Address translation (example in CHS mode)