Introduction to the Computer Busses
The PC receives and sends its data from and to busses. They can be divided into:
- The system bus, which connects the CPU with RAM
- I/O busses, which connect the CPU with other components.
The point is, that the system bus is the central bus. Actually, it connects to the I/O busses, as you can see in this illustration:
You see the central system bus, which connects the CPU with RAM. A bridge connects the I/O busses with the system bus and on to RAM. The bridge is part of the PC chip set.
3 different I/O busses
The I/O busses move data. They connect all I/O devices with the CPU and RAM. I/O devices are those components, which can receive or send data (disk drives, monitor, keyboard, etc. ). In a modern Pentium driven PC, there are two or three different I/O busses:
- The ISA bus, which is oldest, simplest, and slowest bus.
- The PCI bus, which is the fastest and most powerful bus.
- The USB bus, which is the newest bus. It may in the long run replace the ISA bus.
