Serial MIDI: Difference between revisions

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(Expand with info about modes and benefits, and two illustrative photos)
(→‎Overview: mention PC-1 being missing is a USB thing (true of the SC-8850 and MU2000))
 
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[[File:Yamaha QY70 top TO HOST crop.jpg|thumb|right|150px|The TO HOST port on a [[Yamaha QY70]].]]
[[File:Yamaha QY70 top TO HOST crop.jpg|thumb|right|150px|The TO HOST port on a [[Yamaha QY70]].]]
[[File:Yamaha QY70 right HOST SELECT crop.jpg|thumb|right|300px|The HOST SELECT switch on a [[Yamaha QY70]].]]
[[File:Yamaha QY70 right HOST SELECT crop.jpg|thumb|right|300px|The HOST SELECT switch on a [[Yamaha QY70]].]]


Many MIDI modules and similar devices from the 1990's feature a port labelled "'''TO HOST'''" or "'''COMPUTER'''", which can be used with an appropriate cable to connect the device directly to a computer's serial port. This is also sometimes referred to as "'''Serial MIDI'''". From roughly 1999 onwards, USB started to appear alongside or instead of these ports.
Many MIDI modules and similar devices from the 1990's feature a port labelled "'''TO HOST'''" or "'''COMPUTER'''", which can be used with an appropriate cable to connect the device directly to a computer's serial port. This is also sometimes referred to as "'''Serial MIDI'''".
 
Connecting to the computer this way is an alternative to using the normal MIDI ports that does not require use of a MIDI interface. It also often provides additional features, like additional virtual MIDI ports, or being able to use the device as a MIDI interface for connecting additional MIDI devices.
 
From roughly 1999 onwards, USB started to appear alongside or instead of these ports.
 
== Overview ==


Typically, these ports can operate in three to four modes, selected via a switch on the device (usually labelled something like "'''HOST SELECT'''"):
Typically, these ports can operate in three to four modes, selected via a switch on the device (usually labelled something like "'''HOST SELECT'''"):


* A mode designed for the modem port on old Apple Macintosh computers. This mode is usually labelled "'''MAC'''" or "'''RS422'''".
* A mode designed for the modem port on old Apple Macintosh computers. This mode is usually labelled "'''Mac'''" or "'''RS422'''".
* A mode designed for NEC PC-9800 series computers (sold only in Japan). This mode is usually labelled "'''PC-1'''" or "'''RS232C-1'''". Some devices from the later 1990's omit this mode.
* A mode designed for NEC PC-9800 series computers (sold only in Japan). This mode is usually labelled "'''PC-1'''" or "'''RS232C-1'''". Dropped on some devices in favour of USB.
* A mode designed for the 9-pin or 25-pin serial port on IBM PC/AT-compatible computers (common worldwide). This mode is usually labelled "'''PC-2'''" or "'''RS232C-1'''".
* A mode designed for the 9-pin or 25-pin serial port on IBM PC/AT-compatible computers (common worldwide). This mode is usually labelled "'''PC-2'''" or "'''RS232C-2'''".
* A mode where this port is not used, and instead the MIDI ports are used. This mode is usually labelled "'''MIDI'''".
* A mode where this port is not used, and instead the MIDI ports are used. This mode is usually labelled "'''MIDI'''".


Each mode (aside from the MIDI port mode) requires a different, special adapter cable.
Each mode (aside from the MIDI port mode) requires a different, special adapter cable.


Often use of this port to connect to a computer, rather than the MIDI ports, can provide additional features:
== With modern computers ==
 
Modern computers generally do not feature serial ports compatible with this port. Using USB (if available on the module) or a USB MIDI interface (connected to the module's MIDI ports) is usually more practical with modern computers.


* It may make the device function as a MIDI interface.
However, there are alternative solutions. [[User:Valley Bell]] has created an [https://github.com/ValleyBell/UsbSerialMidi open-source hardware project] that allows turning an Arduino board into a serial MIDI to USB MIDI adapter.
* It may allow access to additional MIDI channels (extra virtual "ports").

Latest revision as of 01:50, 14 September 2024

The TO HOST port on a Yamaha QY70.
The HOST SELECT switch on a Yamaha QY70.

Many MIDI modules and similar devices from the 1990's feature a port labelled "TO HOST" or "COMPUTER", which can be used with an appropriate cable to connect the device directly to a computer's serial port. This is also sometimes referred to as "Serial MIDI".

Connecting to the computer this way is an alternative to using the normal MIDI ports that does not require use of a MIDI interface. It also often provides additional features, like additional virtual MIDI ports, or being able to use the device as a MIDI interface for connecting additional MIDI devices.

From roughly 1999 onwards, USB started to appear alongside or instead of these ports.

Overview

Typically, these ports can operate in three to four modes, selected via a switch on the device (usually labelled something like "HOST SELECT"):

  • A mode designed for the modem port on old Apple Macintosh computers. This mode is usually labelled "Mac" or "RS422".
  • A mode designed for NEC PC-9800 series computers (sold only in Japan). This mode is usually labelled "PC-1" or "RS232C-1". Dropped on some devices in favour of USB.
  • A mode designed for the 9-pin or 25-pin serial port on IBM PC/AT-compatible computers (common worldwide). This mode is usually labelled "PC-2" or "RS232C-2".
  • A mode where this port is not used, and instead the MIDI ports are used. This mode is usually labelled "MIDI".

Each mode (aside from the MIDI port mode) requires a different, special adapter cable.

With modern computers

Modern computers generally do not feature serial ports compatible with this port. Using USB (if available on the module) or a USB MIDI interface (connected to the module's MIDI ports) is usually more practical with modern computers.

However, there are alternative solutions. User:Valley Bell has created an open-source hardware project that allows turning an Arduino board into a serial MIDI to USB MIDI adapter.