Fujitsu MCE3130AP, MCF3064AP, MCE3064AP manual

(3)Data buffer

1,844 KB buffer is used to transfer data between the EIDE bus and disk. Since data is stored in this buffer, the host can execute input-output processing effectively by using the high-speed data transfer capability of the EIDE bus without regard to the data transfer rate of the optical disk drive.

(4)Read-ahead cache feature

The read-ahead cache feature enables high-speed sequential data access as follows:

After executing a command to read data from the disk, the drive automatically reads the next data block and stores it in the data buffer (pre-reading). If the next command requests this data, the data is transferred from the buffer without another disk access.

(5)Write cache feature

When the host system issues the write command to the optical disk drive, a command complete is usually responded after completion of the write and verify operations. By using the write cache feature, a command complete is responded after completion of the data transfer to the data buffer without waiting the completion of the write and verify operations then the write and verify operations are made asynchronously with the interface operation. Therefore, the apparent write command processing time measured at the host system is reduced and the I/O performance of the host system is improved.

The write cache feature is enabled or disabled by MODE SELECT command.

When the write cache feature is enabled, a write error is reported at the completion status of next command. At a system so that the host retries the command, a retry process may be failed.

(6)Defective block slipping

When a disk is initialized, logical data blocks are reallocated in a physical sequence by slipping defective data blocks. This enables high-speed continuous data block processing without rotational delay due to defective data blocks.

(7)Device driver software (1.3 GB optical disk media)

The optical disk drive requires more extended processing time than conventional optical device drives because of higher density. Consequently, a processing time timeout when using the OS can occur and this requires special device driver software.

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