computing revision/hardware

computing revision/hardware

1. binary

   • Binary is a mathematical number system: a way of counting. We have all learned to count using ten digits: 0-9. One probable reason is that we have ten fingers to represent numbers. The computer has switches to represent data and switches have only two states: ON and OFF.

2. CPU

   • the CPU is responsible for executing/calculating the programs in a computer system
     • The basic operation of a computer is called the ‘fetch-execute’ cycle. The computer fetches the instruction from its memory and then executes it. This is done repeatedly from when the computer is booted up to when it is shut down.
       • the clock speed is the speed of which the CPU can execute instructions
       • the cache size can have a number of cores, the more cores the more programs a computer system can run
     • memory
       • RAM is random access memory which is memory which cant be saved
       • ROM is read only memory and once data is put onto a ROM chip it can be removed. Even when the computer is off the data is still stored
       • With virtual memory we also use a process called swapping. The process of moving data from RAM to disk (and back) is known as swapping or paging. The Virtual Memory Manager (VMM) is in charge of swapping data between physical memory and the hard disk. As we know, hard drive is a lot slower than RAM.
       • Cache memory, also called CPU memory, is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU
       • a kind of memory that retains data in the absence of a power supply such as USB drives