Below is the diagram. A functional block describes what is done within the block, but in actual hardware may consist of one or more components. Example, mainframe systems may have the CPU plus memory as a separate component.
The term MPU as used here refers to Microprocessor like Intel's P4. Most Desktop PCs use the Intel Processor or equivalent. The Motorola Processor is used by systems like some MAC PCs. Other systems, especially older ones, the CPU Processor consists of a board vs. a MPU.
Notice that drives (hard drives or CD/DVD) can be internal or external.
Here is my first recommendation:
- Through experience I have found using USB connection to external drives (hard drives or CD/DVD) may be unstable. I have found that Firewire connection (via a IEEE 1394 Adapter) to be much more reliable. The adapter is low cost, I got mine for $30, an Adaptec.
- At home I have 3 external Firewire devices. Two hard drives and one DVD-RW DL Recorder. All very reliable. So reliable that I use one external hard drive for my system backup images. We also use external Firewire hard drives for our Fileserver Disaster Recovery backups at work.
- If you do use USB for external drives, make sure you have USB2 support on your motherboard AND USB2 Drivers loaded.