PC Hardware
Inside the PC main unit (Figure 1.2b), the traditional motherboard has slots for expansion boards and memory modules to be added to the system. The power supply and disk drives are fitted separately into the main unit frame. The keyboard and mouse interface are integrated on the motherboard. In older designs, expansion boards carried interface circuits for the disk drives and external peripherals such as the display and printer, but these functions are now increasingly incorporated into the motherboard itself. Peripherals are now usually connected via USB or wirelessly.
The desktop PC is a modular system, which allows the hardware to be put together to meet the individual user’s requirements, with components sourced from different specialist suppliers, and allows subsystems, such as disk drives and keyboard, to be easily replaced if faulty. This also allows easy upgrading (e.g. fitting extra memory chips) and also makes the PC architecture well suited to industrial applications. In this case, the PC can be ‘ruggedized’ (put into a more robust casing) for use on the factory floor. This modular architecture is one of the reasons for the success of the desktop PC hardware, which has continued in the same basic form for many years, as a universal processor platform. The laptop is the main alternative for the general user, but it is not so flexible, and tends to be replaced rather than upgraded. Another reason for its success is the dominance of Microsoft operating systems, which have developed in conjunction with the Intel-based hardware, providing a standard platform for domestic, commercial and industrial computers.