Multisegmented Cache Buffer; Start/Stop Time; Typical Power-Up And Power-Down Sequence; Power-Up Sequence - Seagate ST5660A Product Manual

ST5660A Product Manual, Rev. A 3

1.2.2 Multisegmented cache buffer

The drive uses the 256-Kbyte, multisegmented cache buffer to improve
performance by eliminating access times under certain conditions.
Read look-ahead. The drive uses the read segments to store additional
logical sectors, after the last requested sector, into a buffer before the
additional sectors are requested by the computer. The cache buffer
stores data from the start of a read until the buffer segment is full, or until
another command is received from the computer.
Write immediate. The drive uses the write segment to store write
commands and data. After the drive receives all the data for the com-
mand, it issues a write complete. Then, the drive writes the data to the
disc.
Write merging. The drive accepts contiguous write commands and
executes them as one command.
Write caching. The last data written by the drive is retained in the buffer
for use by future reads.

1.3 Start/stop time

Within 20 seconds after DC power is applied, the drive is ready. Within
15 seconds after DC power is removed, the drive spindle stops rotating.

1.4 Typical power-up and power-down sequence

The typical power-up and power-down sequences assist you in evaluat-
ing the drive's performance; they are not performance specifications.

1.4.1 Power-up sequence

1. Power is applied to the drive.
2. When power is applied, the LED is on for about 1 second.
3. The spindle motor reaches operating speed in about 4 seconds.
4. The magnetic actuator lock releases the actuator.
5. The drive performs velocity adjustment seeks.
6. The heads are positioned over track 0 and the drive is ready.