Cache Memory
Part of the Personal Computer (area of DRAM) that transfers data between system elements with different performance characteristics (increases processing speed)
Capacity
The maximum amount of data that can be stored on a specific HDD, expressed in gigabytes (GB) / megabytes (MB)
Capacity Barriers
On certain occasions (primarily with older Personal Computers) the full capacity of the disk drives in a PC is inaccessible. This may result from a combination of Hardware, BIOS, and Operating System constraints. General solution is either to upgrade the system BIOS or install Driver software
CD-R (also CD Recordable)
A recordable compact disc that holds read only data that cannot be changed
CD-ROM
A pre-mastered compact disc that contains data thanks to an extra recording layer built into the structure of the disc. Once written, the data cannot be erased
CD-RW (CD Re-Writable)
compact disc that allows you to re-record data up to 1000 times
CHS
Cylinders, Heads and Sectors. A term used to describe the properties of hard disk drives, the CHS information for a drive is stored in the computer BIOS
Clean Room
Dust free environment, which is required when manufacturing hard drives
Closed Loop (also track following servo)
Control system, which reflects if the head is in the correct position over the track, if this isn’t the case, the actuator is instructed to adjust its position (in real time)
Component Design Life
The amount of time the drive should operate without any problems
CMOS
Complementary metal oxide semiconductor. CMOS chips are extensively used in computer systems because of their low power consumption. They can also operate over a very wide range of supply voltages. They are, however, susceptible to damage by static electricity and care is required when handling them
CPU
Central Processing Unit, the brain of all modern computers. The microprocessor chip that executes programmed instructions
Crash
breakdown in hardware/software in a system
CRC
CRCCyclic Redundancy Check; part of a sector which detects if parts of a string of data is missing within the sector. It is a method of testing that the data retrieved from a disk is without error. When data is written to disk, a special check number (CRC) is calculated, based on the data itself, and stored with it. As data comes off the disk, the CRC is re-calculated and compared with the stored CRC. The two match if no errors are present
Cylinder
The vertical position of all the heads over the (various) platter(s) on a specific track of a disk drive, forming a vertical cylinder