A. What¡¦s Hard Disk?
- It stores data, programs and the operating system for modern computer.
- It is supported by the drive spindle.
- It is one or more platters.
- Platter (both side) has a read-write head.
- More platters = more data storage capacity.
B. Properties:
- It stores 10 ¡V 100 gigabytes of information.
- Access time: 6 ¡V 11 milliseconds (ms).
C. Where can we find the hard disk?
- Sealed inside the drive case
- To prevent dust from interfering the read-write heads.
D. Working
Principle:
- Read-write head:
o It magnetizes particles on the data storage surface to write data;
o or it senses the bits that are present to read data.
- Hard disk rotates as a unit on spindle to position read-write heads over specific data.
o The above process is helped by drive controller.
o Popular drive controller: Ultra ATA, EIDE and SCSI.
E.
What will happen if the down side of hard disk is damaged?
- Head crash occurs.
- Some of the data on disk would be damage.
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