The universal serial bus (USB) controller acts as an interface between the operating system, device drivers, and applications and the devices that are attached via the USB host.

On a magnetic tape, the inter-record gap (IRG) is about two inches long regardless of the sizes of the records it separates.

Direct access storage devices (DASDs) are devices that can directly read or write to a specific place on a disk.

A fixed-head disk is lower in cost than a movable head disk.

Among the many differences between an optical disc and a magnetic disk is the design of the disc track and sectors.

An optical disc drive adjusts the speed of the disc’s spin to compensate for the sector’s location on the disc—this is called continuous linkage velocity (CLV).

A DVD with a fast data transfer rate will drop fewer frames when playing back a recorded video segment than will a unit with a slower transfer rate.

Blu-ray discs are available in several formats: read-only (BD-ROM), recordable (BD-R), and rewritable (BD-RE).

Each unit in the I/O subsystem can finish its operation independently from the others.

Buffers are used extensively to better synchronize the movement of data between the relatively slow I/O devices and the very fast CPU.

The traffic controller maintains a database containing the status and connections for each unit in the I/O subsystem, grouped into Channel Control Blocks, Control Unit Control Blocks, and Device Control Blocks.

A find strategy determines the order in which the processes get the I/O handler device, and the goal is to keep seek time to a minimum.

First-come, first-served (FCFS) is the simplest device-scheduling algorithm.

The SCAN algorithm moves the arm methodically from the inner to the outer track, servicing every request in its path.

RAID is a set of logical disk drives that is viewed as a single physical unit by the operating system.

Most RAID configurations require fewer disk drives, which decreases hardware costs.

RAID Level 0 is the only one that does not provide error correction, or redundancy, and so it is not considered a true form of RAID because it cannot recover from hardware failure.

The advantage of RAID Level 3 is that if any one drive fails, data can be restored using the bits in the parity disk.

Additional complex configurations of RAID can be created by combining multiple levels.

____ devices are assigned to only one job at a time.

The USB controller assigns bandwidth to each device depending on its priority, and the ____ priority is assigned to real-time exchanges where no interruption in the data flow is allowed, such as video or sound data.

The number of characters that can be recorded per inch on a magnetic tape is determined by the ____ of the tape.

If the transport speed for a magnetic tape is 200 inches per second and the density is 1600 bpi, a total of ____ bytes can be transferred in one second.

It takes 2.5 minutes to reach the last record on a tape, ____ is the average access time.

In a fixed-head magnetic disk, each circle is called a ____.

Movable-head magnetic disks, such as the computer hard drive, have ____ read/write head(s).

The advent of optical discs was made possible by developments in ____ technology.

On an optical disc, all sectors are ____.

The data-transfer rate for an optical disc is measured in ____ per second and refers to the speed at which massive amounts of data can be read from the disc.

To put data on an optical disc requires a high-intensity laser beam, which burns indentations, called pits, and flat areas, called ____.

The software used to create a CD-R uses a standard format, such as ____, which automatically checks for errors and creates a table of contents, used to keep track of each file’s location.

A dual-layer, single-sided DVD can hold the equivalent of ____ CDs.

Data recorded on fixed-head DASDs may or may not be blocked at the discretion of the ____.

Of the three components of access time in a movable-head DASDs, ____ is the longest.

____ control the transfer of information between the disk drives and the rest of the computer system.

The I/O ____ allocates the devices, control units, and channels.

____ uses the same underlying philosophy as shortest job next, where the shortest jobs are processed first and longer jobs are made to wait.

The RAID level ____ uses word parity for error correction.

The RAID level ____ requires two different parity calculations.