PC design: Architecture: Trading off technical innovation against the dependability of established standards is a principal consideration for PC designers

The problems faced by all PC architectures are summarized. It is pointed out that in addition to market forces and technical constraints, PC manufacturers have to contend with the Federal Communications Commission, which can keep them out of the market altogether. Every personal computer sold in the United States must meet the FCC´s radio-frequency emission standards. The single architectural decision that has raised the most controversy in personal computers is that of open versus closed architectures: should a PC leave room for augmentation by add-on cards and new software, or should it be a closed system that performs a limited range of functions very efficiently? On the physical side of the design, the decision comes down to whether a computer should have expansion slots into which new boards can be plugged, and this issue is examined.