Managing MIDI Ports
Before reading this topic, you should review Understanding Ports and Devices in the MIDI Device Configuration Window.
A MIDI port is something that Microsoft Windows abstractly defines. Basically, a MIDI port identifies the "place" where a MIDI application, such as Composer, "talks" to a particular MIDI sound-producing device. Except in the MIDI Device Configuration Window, Composer always refers to devices, not ports. The MIDI Device Configuration Window is the place where you inform Composer how external devices are connected to ports.
When Composer runs for the first time, or whenever it detects the presence of a MIDI port, it detects whether each MIDI port is an internal or external port. For an explanation of internal versus external, see Understanding Ports and Devices in the MIDI Device Configuration Window. This detection is based on information provided by the MIDI driver for the port. A few MIDI drivers incorrectly report this information. Therefore, Composer offers you the option to correct the specification of whether a port is internal or external. See Specifying Whether a Port is Internal Or External.
Composer enforces a rule that an internal MIDI port must always be associated with a corresponding internal device.
An external input or output port can be connected to one or more external devices. You can use the Connect to External Device command in the Port menu to establish the connection between an external port and an external device. See Connecting and Disconnecting Devices from an External Device.