Fujitsu MAP3147NC/NP Computer Drive User Manual


 
1-8 C141-E166
(5) Air circulation (recirculation filter, breather filter)
The disk enclosure (DE) configures a sealed room to keep out dust and other pollutants. The DE
has a closed-loop air recirculation system. Using the movement of the rotating disks, air is
continuously cycled through a filter. This filter will trap any dust generated inside the enclosure
and keep the air inside the DE contaminant free. To prevent negative pressure in the vicinity of the
spindle when the disks begin rotating, a breather filter is attached. The breather filter also
equalizes the internal air pressure with the atmospheric pressure due to surrounding temperature
changes.
(6) Read/write circuit
The read/write circuit utilizes a read channel mounted with a head IC that supports high-speed
transmission and an MEEPR4ML (Modified Enhanced Extended Partial Response Class 4
Maximum Likelihood) modulation/demodulation circuit in order to prevent errors being triggered
by external noise and to improve data reliability.
(7) Controller circuit
The controller circuit uses LSIs to increase the reliability and uses a high speed microprocessing
unit (MPU) to increase the performance of the SCSI controller.