Overview of Computer HardwareOverview of Computer Hardware
Computer GenerationsClassification of Computer SystemComputer System Concept Computer Peripherals
Computer GenerationsComputer Generations
First Generation Computer– Early 1950s.– Used thousands of vacuum tubes for processing
and memory switching.– Used magnetic drums or tape secondary storage– Used paper tape as Input and Output media.– Has main memory of only a few thousand
character.
Computer GenerationsComputer Generations
Second Generation Computer– Late 1960s.– Used transistors and other solid-state
semiconductor devices.– Main memory capacities of less than 100
kilobytes.– Magnetic disk packs and magnetic tape were
used as I/O and secondary storage medium.
Computer GenerationsComputer Generations
Third Generation Computers– 1970s– Used integrated circuits.– Main memory capacities increased to several
megabytes.– Possible used of operating system program.– Wide spread use of small computer called
microcomputer.
Computer GenerationsComputer Generations
Fourth Generation Computers– 1980s and 1990s– Used LSI and VLSI technologies.– Used microprocessor.– Magnetic core memory is replaced by memory chips.– Main memory capacity ranging from a few megabytes
to several gigabytes.
Fifth Generation Computer– as we enter 21st century.
Classification of Computer SystemClassification of Computer System
Microcomputer SystemMidrange Computer SystemMainframe Computer System
Classification of Computer SystemClassification of Computer System
Microcomputer System– Usually called personal computer or PC.– Variety of size and purpose, e.g. handheld, notebook,
desktop.– Workstation computers– Network servers– Personal Digital Assistants (PDA)– Multimedial PC– Network Computer.
Classification of Computer SystemClassification of Computer System
Network computer
Classification of Computer SystemClassification of Computer System
Midrange Computer System– Multi-user system that can manage networks of PCs and
terminals.– Includes minicomputers and high-end network servers.– Not as powerful as mainframe computers but less costly
to buy, operate and maintain than mainframe system.– Serves as industrial process-control and manufacturing
plant computers.
– Popular as network server.
Classification of Computer SystemClassification of Computer System
IBM Netfinity 7000
Classification of Computer SystemClassification of Computer System
Mainframe Computer System– Large, fast and powerful computer.– Can process hundreds of million instruction per second.– Has large primary storage capacity.– Handle information processing needs of major corporatio
n and government agencies or with complex computational problems.
– Used as superserver for large client/networks and high volume internet website.
– Supercomputer
Classification of Computer SystemClassification of Computer System
IBM S/390
Classification of Computer SystemClassification of Computer System
Supercomputer IBM RS/6000 SP
Computer System ConceptComputer System Concept
Computer is a system of hardware devices organized according to the following system functions
Input Processing Control Output Storage
Computer System ConceptComputer System Concept
Computer System ConceptComputer System Concept
Central Processing Unit (CPU)– most important hardware component of a comp
uter system– divided into two subunits
Arithmetic-Logic Unit or ALU Control Unit
Computer System ConceptComputer System Concept
Intel Pentium II microprocessor
Computer System ConceptComputer System Concept
Primary Storage– commonly called main memory– holds data and program instruction between pro
cessing step– most computer memory consists of microelectr
onic semiconductor memory chips known as RAM ( Random Access Memory ) ROM ( Read Only Memory )
Computer System ConceptComputer System Concept
Secondary Storage– devices like magnetic disks, optical disk ,etc.– has larger storage capacity than computer main
memory– play supporting role to primary storage and co
mputer system.
Computer System ConceptComputer System Concept
Multiple Processor Designs.– Support Processor
relies on specialized microprocessors to help the main CPU perform a variety of functions.
E.g. arithmetic co-processor, video display controller, etc.
– Coupled Processor uses multiple CPU or main microprocessor. Executing more than one instruction at the same time.
Computer System ConceptComputer System Concept
Multiple Processor Designs (continued)– Parallel Processor
uses group of instruction processor to execute several program instruction in parallel.
hundreds or thousands of processor are organized in network.
– RISC Processor Reduced Instruction Set Computer uses smaller number of basic machine instruction. Required more complex software.
Computer PeripheralsComputer Peripherals
Input Technologies– keyboard– pointing device. E.g. electronic mouse, track ball, po
inting stick, touch pad, touch screen– pen-based computing– voice recognition and response– optical scanning– magnetic stripe– digital cameras
Computer PeripheralsComputer Peripherals
Output Technologies– Video output
Video monitor Liquid Crystal Display (LCD)
– Printed output Inkjet printer Laser printer
Computer PeripheralsComputer Peripherals
Pen-based tablet recognizes handwriting on its display screen
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