These tiny toggle or slide switches are mounted directly onto printed circuit boards to set hardware configurations. Each individual switch in the block represents a single bit of binary data, allowing users to select device addresses, baud rates, or operational modes without needing a software interface. They were heavily used in older hardware before plug-and-play standards became widespread, but remain common in industrial controls and development boards.
Heard on the job
Set the DIP switch on the backplane to address four before you slot in the new expansion card.
Insider tip
Always use a small flathead screwdriver or a dedicated tool to flip these; using a ballpoint pen can leak ink into the contacts and ruin the switch mechanism.