MIS 180 Chapter Notes - Chapter Appendix A : Data Management, Laser Printing, Photocopier
31 May 2018
School
Department
Course
Professor
Appendix Notes
Appendix A
Hardware and Software Basics
Introduction
Hardware - consists of the physical devices associated with a computer system
Software - set of instructions the hardware executes to carry out specific tasks
Hardware Basics
Computer - an electronic device operating under the control of instructions stored in its own memory that can
accept, manipulate, and store data
Consists of six hardware components
Central processing unit (CPU) - actual hardware that interprets and executes the program instructions and
coordinates how all the other hardware devices work together
Built on a small flake of silicon and can contain the equivalent of several million transistors
Control unit - interprets software instructions and literally tells the other hardware devices what to do,
based on the software instructions
Arithmetic-logic unit (ALU) - performs all arithmetic operations and all logic operations
Megahertz (MHz) - number of millions of CPU cycles per second
Gigahertz (GHz) - number of billions of CPU cycles per second
Clock speed - speed of the internal clock of a CPU that sets the pace at which operations proceed within
the computer's internal processing circuitry
Word length - number of bits (0s and 1s) that can be processed by the CPU at any one time
Bus width - size of the internal electrical pathway along which signals are sent from one part of the
computer to another
Chip line width - distance between transistors on chip
Complex instruction set computer chips (CISC) - type of CPU that can recognize as many as 100 or more
instructions, enough to carry out most computations directly
Reduced instruction set computer chips (RISC) - limit the number of instructions the CPU can execute to
increase processing speed
To reduce the instruction set to the bare minimum, emphasizing the instructions used most of the time
and optimizing them for the fastest possible execution
Primary Storage
Primary storage - computer's main memory, which consists of the random access memory, cache memory, and
read-only memory that is directly accessible to the CPU
Random access memory (RAM) - computer's priory working memory, in which program instructions
and data are stored so that they can be accessed directly by the CPU via the processor's high-speed
external data bus
CPU can write and read data
Does not retain its contents when the power to the computer is switched off
Volatility - RAM's complete loss of stored information if power is interrupted
Cache memory - small unit of ultra-fast memory that is used to store recently accessed or frequently accessed
data so that the CPU does not have to retrieve this data from slower memory circuits such as RAM
Read-only memory (ROM) - portion of a computer's primary storage that does not lose its contents when one
switches off the power
Contains essential system programs that neither the user nor the computer can erase
Flash memory - special type of rewritable read-only memory that is compact and portable
Memory cards - contain high-capacity storage that holds data such as captured images, music, or text
files
Memory sticks - proved nonvolatile memory for a Rangel of probable devices
Secondary Storage
Secondary storage - consist of equipment designed to store large volumes of data for long-term storage
These devices are nonvolatile and do not lose their contents when the computer is turned off
Megabyte (MB) - roughly 1 million bytes
Bytes = characters of data and software instructions
Gigabyte (GB) - roughly 1 billion bytes
Terabyte (TB) - roughly 1 trillion bytes
Magnetic medium - secondary storage medium that uses magnetic techniques to store and retrieve data on disks
or tapes coated with magnetically sensitive materials
Magnetic tape - older secondary storage medium that uses a strip of thin plastic coated with a
magnetically sensitive recording medium
Hard drive - secondary storage medium that uses several rigid disks coated with a magnetically
sensitive material and house together with the recording heads in a hermetically sealed mechanism
Optical medium - secondary storage medium for computers on which information is stored at extremely high
density in the form of tiny pits
Compact disk-read-only memory drive (CD-ROM) - an optical drive designed to read the data encoded
on CD-ROMs and to transfer this data to a computer
Compact disk-read-write drive (CD-RW) - an optical drive that enables users to erase existing data and
to write new data repeatedly to a CD-RW
Digital video disk (DVD) - CD-ROM format capable of storing up to a maximum of 17 GB of data
DVD-ROM drive - a read-only drive designed to read the data encoded on a DVD and transfer the data
to a computer
Digital video disk-read/write (DVD-RW) - standard for DVD discs and player/recorder mechanisms
that enables users to record in the DVD format
Input Devices
Input device - equipment used to capture information and commands
Document Summary
Hardware - consists of the physical devices associated with a computer system. Software - set of instructions the hardware executes to carry out specific tasks. Computer - an electronic device operating under the control of instructions stored in its own memory that can accept, manipulate, and store data. Central processing unit (cpu) - actual hardware that interprets and executes the program instructions and coordinates how all the other hardware devices work together. Built on a small flake of silicon and can contain the equivalent of several million transistors. Control unit - interprets software instructions and literally tells the other hardware devices what to do, based on the software instructions. Arithmetic-logic unit (alu) - performs all arithmetic operations and all logic operations. Megahertz (mhz) - number of millions of cpu cycles per second. Gigahertz (ghz) - number of billions of cpu cycles per second.
