Port expander

A port expander is computer hardware that allows more than one device to connect to a single port on a computer. The Commodore VIC-20, for example, used a port expander to allow more than one cartridge to connect to the single ROM cartridge port.

A port expander can be any device to which one existing or onboard port becomes two or more - for example: a KVM switch or a USB hub. Such expanders offer the advantage of allowing more devices of a particular port type to be utilized at the same time. A major downside is that, for example, a 3Gbit/s port might have a hub or expander installed and now be able to accommodate 6 devices, but at a maximum of 3Gbit/s throughput bandwidth divided by the said 6 devices, or by however many are plugged in and being used. A port expander is a device that allows one port on a computer system to connect to multiple devices. Two basic forms of port expander exist: internal and external. An internal expander has a connection inside the computer, typically on the motherboard, and the only part the user sees is the expansion plate containing multiple ports. An external device plugs into the existing port and then has multiple places to connect. When not part of a computer system, these devices are commonly known as splitters.