Address Translation; Default Parameters - Fujitsu MPG3409AT Product Manual

6.2

Address Translation

When the IDD receives any command which involves access to the disk medium, the IDD always
implements the address translation from the logical address (a host-specified address) to the
physical address (logical to physical address translation).
Following subsections explains the CHS translation mode.
6.2.1

Default parameters

In the logical to physical address translation, the logical cylinder, head, and sector addresses are
translated to the physical cylinder, head, and sector addresses based on the number of heads and
the number of sectors per track which are specified with an INITIALIZE DEVICE
PARAMETERS command. This is called as the current translation mode.
If the number of heads and the number of sectors are not specified with an INITIALIZE DEVICE
PARAMETERS command, the default values listed in Table 6.1 are used. This is called as the default
translation mode. The parameters in Table 6.1 are called BIOS specification.
Formatted
capacity (MB)
MPG3102AT 10,248
MPG3153AT 15,371
MPG3204AT 20,496
MPG3307AT 30,743
MPG3409AT 40,992
As long as the formatted capacity of the IDD does not exceed the value shown on Table 6.1, the
host can freely specify the number of cylinders, heads, and sectors per track.
Generally, the device recognizes the number of heads and sectors per track with the INITIALIZE
DEVICE PARAMETER command. However, it cannot recognizes the number of cylinders. In
other words, there is no way for the device to recognize a host access area on logical cylinders.
Thus the host should manage cylinder access to the device.
The host can specify a logical address freely within an area where an address can be specified
(within the specified number of cylinders, heads, and sectors per track) in the current translation
mode.
The host can read an addressable parameter information from the device by the IDENTIFY
DEVICE command (Words 54 to 56).
6 - 6
Table 6.1 Default parameters
Parameters (logical)
Number of cylinders Number of heads
16,383
C141-E110-03EN
Number of sectors/track
16 63