Elliot B. Koffman > Quotes

“Flash drives such as the one pictured in Fig.1.6 use flash memory packaged in small plastic cases about three inches long that can be plugged into any of a computer's USB (Universal Serial Bus) ports. Unlike hard drives and optical drives that must spin their disks for access to data, flash drives have no moving parts and all data transfer is by electronic signal only. In flash memory, bits are represented as electrons trapped in microscopic chambers of silicon dioxide.”
― Elliot B. Koffman

“The circuitry of a modern CPU is housed in a single integrated circuit or chip, millions of miniature circuits manufactured in a sliver of silicon. A processor's current instruction and data values are stored temporarily inside the CPU in special high-speed memory locations called registers.

Some multiprocessor computers have multiple CPU chips or a multi-core processor (a single chip containing multiple CPUs). These computers are capable of faster speeds because they can process different sets of instructions at the same time.”
― Elliot B. Koffman, Problem Solving and Program Design in C

“Many of today's personal computers are equipped with optical drives for storing and retrieving data on compact discs (CDs) or digital versatile disks (DVDs) that can be removed from the drive. A CD is a silvery plastic platter on which a laser records data as a sequence of tiny pits in a spiral track on one side of the disk. One CD can hold 680 MB of data. A DVD uses smaller pits packed in a tighter spiral. Some Blu-ray disks (high-density optical disks read with a blue-violet laser) can hold multiple layers of data-for a total capacity of 200GB, sufficient storage for many hours of studio-quality video and multi-channel audio.”
― Elliot B. Koffman, Problem Solving and Program Design in C

“Most personal computers use two types of disk drives as their secondary storage devices-hard drives and optical drives. Hard disks are attached to their disk drives and are coated with a magnetic material. Each data bit is a magnetized spot on the disk, and the spots are arranged in concentric circles called tracks. The disk drive read/write head accesses data by moving across the spinning disk to the correct track and then sensing the spots as they move by.”
― Elliot B. Koffman, Problem Solving and Program Design in C