External Memory in Computer Organization Quiz

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Questions and Answers

What is the difference between traditional and contemporary read heads in magnetic storage devices?

Contemporary read heads have a larger coil, while traditional read heads have a smaller coil.
Contemporary read heads use inductive write/magneto-resistive read heads, while traditional read heads use a different technology.
Contemporary read heads have a separate read head close to the write head, while traditional read heads do not. (correct)
Contemporary read heads operate at lower frequencies, while traditional read heads operate at higher frequencies.

How are data organized on the platter in magnetic storage devices?

Data are organized in a concentric set of rings called tracks, with each track having the same width as the head. (correct)
Data are organized in a spiral pattern starting from the outer edge of the platter.
Data are organized in a linear fashion from the center of the platter to the outer edge.
Data are organized randomly across the platter to optimize storage density.

What determines the electrical resistance in contemporary read heads of magnetic storage devices?

The frequency of operation
The direction of the magnetic field (correct)
The speed of the platter rotation
The size of the platter

How are adjacent tracks organized on the platter in magnetic storage devices?

<p>Adjacent tracks are separated by gaps to minimize errors due to misalignment of the head and interference of magnetic fields. (D)</p> Signup and view all the answers

What is the purpose of sectors in data organization on the platter in magnetic storage devices?

<p>Data are transferred to and from the disk in sectors, which can be fixed-length or variable length. (C)</p> Signup and view all the answers

Flashcards

Contemporary Read Heads

Contemporary read heads have a separate read head close to the write head.

Data Organization on Platter

Data is organized in concentric rings called tracks, each with the same head width.

Resistance in Contemporary Heads

Resistance in contemporary read heads is determined by the magnetic field's direction.

Adjacent Track Separation

Adjacent tracks are separated by gaps to prevent head misalignment and field interference.

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Sectors in Data

Data is transferred in sectors, which can be fixed or variable length.

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Study Notes

External Memory

Types of external memory include magnetic disk, optical memory, and magnetic tape.

Magnetic Disk

A magnetic disk consists of a circular platter made of non-magnetic material (substrate) coated with a magnetizable material.
Traditional substrates are made of aluminum or aluminum alloy, but recently glass substrates have been introduced.
Glass substrates offer several advantages, including: • Improved surface uniformity to increase reliability • Reduced surface defects to reduce read/write errors • Support for lower fly heights • Better stiffness to reduce disk dynamics • Better shock/damage resistance

Magnetic Disk Read and Write Mechanisms

Data is recorded and retrieved using a conductive coil called a head.
There may be a single read/write head or separate heads for each function.
During read/write operations, the head is stationary, while the platter rotates.
The write process involves: • Current flowing through the coil to produce a magnetic field • Pulses sent to the head • A magnetic pattern recorded on the surface below