hardware
equipment and devices that perform
software
Evolution of Computer Hardware
1st gen: electromechanical calculators
2nd gen: vacuum tube computers
3rd gen: transistor computers
4th gen: integrated circuit computers
5th gen: very large-scale integration (VLSI) computers
6th gen: parallel processing, artificial intelligence (speculative)
Computer architecture
mircocomputers
- lack extensive peripherals and storage
minicomputers
mainframes
- can have many programs running simultaneously
supercomputers
- used for specific data analysis and engineering design
microprocessors
a CPU on a single chip which controls the flow of data between the CPU, memory, and input/output devices
components of microprocessor
control unit
fetch
execute
manages the execution of these steps, potentially involving
arithmetic logic unit (ALU)
accumulators
stacks
registers
used for temporary storage of instructions of data
special registers:
–> program counter: always points to the address of the next instruction
instruction register:
–> holds the current instruction during execution
microprocessor communications
a bus is the physical path that the signal travels along, such as wires or circuit board traces
A channel is a logical path
buses have various functions:
system bus
incorporates the address bus, data bus, and control bus
address bus
transmits the location in memory that is being read from or written to
data bus
control bus
communicates control and status information to initiate and terminate read/write operations, enable chips, and signal bus/available status
transmission includes:
fetch step
i/o device or main memory chip select and data flow direction are loaded onto the control bus
i/o device port number or memory location within a memory chip is loaded onto the address bus
operation to be performed (op-code) is loaded onto the data bus
execute step
- cycle continually repeats