A standard serial interface (EIA/TIA-232-E) configuration. The format is widely supported for bi-directional data transfer at low to moderate rates. It has been used on many personal computers over the years to connect personal computers with peripheral hardware and instruments (such as MIDI interfaces). Use is restricted to one peripheral at a time and short distances. The standard originally called for DB-25 connectors, but now allows the smaller DB-9 version (see WFTD D-Sub).