ABSTRACT
Different connectors - there are so many different types of connectors for many different types of devices that connect to the PC. For example, the keyboard uses a 5-pin DIN plug, the parallel port uses a 25-pin D-type connector, the primary serial port uses a 9pin D-type connector, the video adaptor uses a 15-pin D-type connector, and so on. The hture is likely to bring a standardisation of these connectors, possibly with the USB port. Different configurations - typically different peripherals required assigned interrupts and I/O addresses. For example, the keyboard uses IRQl and I/O ports at 60h and 64h. This is now being overcome by busses such as SCSI and USB, which only require a single interrupt and a limited range of addresses. They also cope better with hot plug-andplay devices and operating system configurable devices. Different data traffic rates - relatively low speed interfaces, such as the ISA bus, have often reduced the rate of other faster busses, such as the PCI bus. This is now being overcome by the use of bridges and the USB bus.
