xref: /netbsd-src/share/man/man4/midi.4 (revision bada23909e740596d0a3785a73bd3583a9807fb8)
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34.Dd August 6, 1998
35.Dt MIDI 4
36.Os
37.Sh NAME
38.Nm midi
39.Nd device-independent MIDI driver layer
40.Sh SYNOPSIS
41.Cd "midi* at opl?"
42.Cd "midi* at pcppi?"
43.Cd "midi* at sb?"
44.Cd "midi* at wss?"
45.Cd "pseudo-device sequencer"
46.Pp
47.Fd #include <sys/types.h>
48.Fd #include <sys/midiio.h>
49.Sh DESCRIPTION
50The
51.Nm
52driver provides support for various MIDI peripherals.
53It provides a uniform programming interface layer above different
54underlying MIDI hardware drivers.  The MIDI hardware can be of many
55different kinds, e.g., an external synthesizer on a MIDI port (or a serial port),
56the PC speaker, an internal FM synth, or a wavetable synth.
57.Pp
58There are two device file types available for MIDI operation:
59.Pa /dev/rmidiN ,
60and
61.Pa /dev/music .
62The
63.Pa /dev/rmidiN
64devices provides raw access to a MIDI device.  Data written is sent
65to the physical device as fast as possible and is uninterpreted.
66Reading from the device returns data as soon as it becomes available.
67A moderate amount of buffering is available both for reading and writing.
68The raw MIDI devices are mostly useful for non realtime operations, such as
69downloading patches to a device, since it is hard to get the accurate timing
70needed for quality music from a user program.  But the devices can act as
71a simple patchboard for MIDI devices.  For example, a MIDI keyboard could
72be connected to a synthesizer by the command
73.Cd "cat -u /dev/rmidi1 >/dev/rmidi2"
74.Pp
75The
76.Pa /dev/music
77device is a MIDI sequencer device.  Data sent to and from this device
78not only contains the information sent to the MIDI device, but also
79timing information.  The kernel will make sure that data is sent
80to the physical device at the indicated time.  The sequencer device
81uses the
82.Pa /dev/midiN
83devices internally and they are unavailable when used by the sequencer.
84.Pp
85The API for the sequencer device is binary compatible with the OSS sequencer
86interface.
87.Sh FILES
88.Bl -tag -width /dev/sequencer -compact
89.It Pa /dev/rmidiN
90.It Pa /dev/music
91.It Pa /dev/sequencer
92.El
93.Sh SEE ALSO
94.Xr audio 4 ,
95.Xr ioctl 2 ,
96.Xr midiplay 1 ,
97.Xr opl 4 ,
98.Xr ossaudio 3 .
99.br
100For ports using the ISA bus:
101.Xr pcppi 4 ,
102.Xr sb 4 ,
103.Xr wss 4 .
104.Sh HISTORY
105The
106.Nm
107driver first appeared in
108.Nx 1.4 .
109.Sh BUGS
110This man page is very incomplete.
111.Pp
112