The Digital World vs The Real World Computers “speak” in terms of the binary language (“1” and “0”) which represent on and off pulses of electricity.Computers “speak” in terms of the binary language (“1” and “0”) which represent on and off pulses of electricity. Digital is very discreet - either the pulse is there or it isn’t.Digital is very discreet - either the pulse is there or it isn’t. Our world is not discreet. We “speak” and hear along a continuous analog wave.Our world is not discreet. We “speak” and hear along a continuous analog wave. Our language is not discreet. What humans recognize as language must be converted to machine language.Our language is not discreet. What humans recognize as language must be converted to machine language.

A “machine cycle” is the amount of time that it takes for a computer to:A “machine cycle” is the amount of time that it takes for a computer to: –Fetch and instruction from RAM (which has been put there as an input process from our world) –Decode the instruction into machine language –Execute the instruction inside of the ALU –Return the result back to RAM (which is then returned to us as an output process by the OS) Measured in terms of MHz or MIPS (millions of instructions per second)Measured in terms of MHz or MIPS (millions of instructions per second) The Digital World vs The Real World

Classification of computer systems MicrocomputersMicrocomputers MainframesMainframes SupercomputersSupercomputers

Microcomputers Personal computer: single-user computer. Desktop model, laptop, notebook, subnotebook, Personal Digital Assistants (PDAs)Personal computer: single-user computer. Desktop model, laptop, notebook, subnotebook, Personal Digital Assistants (PDAs) Workstations: special PCs designed to support applications that require more power than ordinary personal computing.Workstations: special PCs designed to support applications that require more power than ordinary personal computing. Embedded: microcomputer is embedded inside of another machine.Embedded: microcomputer is embedded inside of another machine. Convergent TechnologiesConvergent Technologies Network computersNetwork computers

Supercomputers Usually several large integrated computers. Used primarily in defense and scientific organizations to process enormous amounts of data extremely fast.Usually several large integrated computers. Used primarily in defense and scientific organizations to process enormous amounts of data extremely fast. Finding more use in traditional transaction environments.Finding more use in traditional transaction environments.

Mainframe Large centralized computers. Normally used to process operational business transactions. Some firms may have more than one mainframe.Large centralized computers. Normally used to process operational business transactions. Some firms may have more than one mainframe. Usually supports hundreds or thousands of users.Usually supports hundreds or thousands of users. Large data storage abilityLarge data storage ability