systems architecture

systems architecture

1. main memory

   • RAM (Random Access Memory)
     • - holds data and instructions that are currently in use, volatile
     • located on the motherboard, directly accessible by the processor
   • ROM (Read Only Memory)
     • non- volatile, holds bootstrap loader, stores BIOS
     • instructions are permanently etched onto a ROM chip
   • EEPROM (Electronically erasable programmable read only memory
     • E.g sim cards, flash memory
     • instructions/ data can be erased electronically and replaced

2. system buses

   • bus- a set of parallel wires connecting two or more independent components of a computer system in order to pass signals between them
   • data bus -carries the data between the processor and other components, bi-directional, data can be read/written