chapter 2 hardware trends in computing systems generally classified into three groups –mainframe...
TRANSCRIPT
Chapter 2Hardware
• Trends in Computing Systems
• Generally classified into three groups– Mainframe computers– Midrange (mini) computers– Microcomputers (PCs)
MicrocomputerApplications
• Often referred to as personal computers
• Many uses, styles, purposes
• Workstations - High power PCs used for analytical processing, mathematical calculations, statistical analysis
• Network Servers - Used to manage resources on a network (usually a Local Area Network)
Microcomputers (cont)
• Personal Digital Assistants - Highly specialized and mobile devises
• Use special software to allow for optical character recognition, touch pads, pen-based interface, etc.
• This is the latest trend in communications devices
Multimedia Systems
• Personal computers with a variety of media devices
• Allow for more robust displays, music, voice recognition and synthesis
• More expensive than a traditional machine, but much more useful and capable
Network computers
• Designed primarily for work situations where users access an Intranet (network using Internet technologies
• These machines usually have little or no disk storage space
• Main benefits are low cost, ease of upgrades, manageable
Computer terminals
• Dumb terminal - No processing occurs at the terminal level. Usually associated with a mainframe or client/server system
• Intelligent terminals - Have the capability to process at the local level (includes transaction terminals in grocery store, banks, department stores, etc)
Midrange Systems
• Multi user systems that manage network traffic, file access, device management
• More powerful than a personal computer
• Less powerful than a mainframe
• Less costly to purchase, operate, maintain
• Most efficient when scope of use is narrow but processing needs are high
Midrange (cont)
• Used largely in scientific research, process control situations, engineering (CAD, CAM, CAO)
• Sometimes used as front end processors to aid a mainframe system
• Good devices for telecommunications and network control (network servers)
Midrange (cont)
• Can be used to host an Intranet, Extranet, Internet, or client/server system
• Can be configured and programmed to operate virtually unaided
• Do not require special climate controlled areas
Mainframe Systems
• Physically larger than midrange, microcomputers, file servers
• Can process more data and faster
• Processing measured in MIPS (millions of instructions per second)
• High storage capacity
• Require climate controlled operating areas
Mainframe Applications
• Support the information and processing needs of large corporations, government offices, military
• Can handle vast computational tasks
• Super-server for communications need of large client/server networks
• Data warehousing
Supercomputer Applications
• Used by major universities, multinational corporations, largest government divisions
• Cooperative applications between countries
• Use multiple processors (any of which could constitute as a mainframe)
• $5million to $50 million cost
Components of a Computer System
• It is important to understand the components of a computer as a system
• Input > Processing > Output > Storage > Control
Input
• Input devices allow for the feeding of data to the computer system
• Keyboard/keypad
• Touch screen
• Light pens
• Mouse
• OCR
• Voice activation
Processing
• Central processing unit (microprocessor in a personal computer)
• Performs three functions– Control unit– Arithmetic-Logic unit– Primary storage unit
Output
• Processed data in the form designated by the user
• Devices include– video display (monitors)– Audio response– Printers
Storage
• Used to store programs (computer instructions), data, processed information
• Two types– Primary storage (main memory)– Secondary storage (magnetic disk, compact
disc, magnetic tape)
Control
• The control unit manages and interprets programs, transmission to other components of the system
• Is part of the CPU– other part is ALU– CPU contains cache memory
Primary Storage
• Main memory - microelectronic semiconductors
• Commonly known as RAM (random access memory)
• Sometimes main memory can use ROM (read only memory)
• Loss of data if power loss
Secondary storage
• Commonly known as permanent storage
• Physical storage versus electronic storage
• Support for primary storage
Multiple Processor Systems
• Some systems use more than one processor unit
• Several configurations
• Usually splits the control unit and the logic unit
Multi ProcessorConfigurations
• Support Processor - Free up the main processor to execute program instructions (can be a math co-processor, video display controller or magnetic disk controller)
• Coupled Processor - Used mostly to provide for fault tolerance
• Parallel Processors - Execute instructions in sequence
cont
• Massively Parallel Processors - Many processors aligned to execute hundreds or thousands of instructions at the same time
• RISC - Reduced Instruction Set Computer
• Uses less instructions
• Conclude chapter 2 next week
• Complete coverage of chapter 3 next week