Direct cable connection to a standard serial cable) must be used to connect each of the two computers to communicate properly. Such connection uses PPP protocol. If the parallel ports are used, Windows supports standard or basic 4-bit cable (commonly known as LapLink cable), Enhanced Capabilities Port (ECP) cable, or Universal Cable Module (UCM) cable (which was known as DirectParallel cable by Parallel Technologies). Infrared communication ports, like the ones found on laptop computers (such as IrDA), can also be used. Connecting any two computers using USB requires a special proprietary bridge cable. A directly connected pin-to-pin USB type A cable does not
Parallel and counter parallel major and tL in minor. If chords may be formed by raising (major) or lowering (minor) the fifth a whole step ["parallel" or relative chords], they may also be formed by lowering (major) or raising (minor) the root a half-step to "wechsel", the leading tone or "leitton". For example, Am is the tonic parallel of C, thus, Em is the counter parallel of C. The usual parallel chord in a major key is a minor third below the root and the counter parallel is a major third above. In a minor key the intervals are reversed: the tonic parallel (e.g.