Introduction

MIDI Through does what it says. It connects your BeOS computer's MIDI outputs to its MIDI inputs and to the internal MIDI synth. You can turn off or on the connections between each MIDI input and output. By default, all inputs are connected to all outputs and to the MIDI synth.

MIDI Port Window

To turn the connection between a MIDI input and a MIDI output on or off, click the corresponding check box. The current port connection settings are saved whenever you quit MIDI Through

The panic button sends all-notes-off messages on all MIDI channels to all MIDI output ports. Even if a MIDI output is not connected to any MIDI inputs, the all-notes-off message is still sent to that output.

Internal MIDI Synth Window

The Internal Synth window displays a program name popup menu and a volume slider for each MIDI channel. You can select programs and adjust the volume of each channel.

When you send a MIDI program change or volume command, the corresponding popup menu or slider is updated.

The General MIDI spec defines channel 10 as the drum channel. At first glance it may seem unnecessary to provide a program change popup menu for channel 10. However, not all synths are General MIDI and many treat channel 10 the same as any other MIDI channel.

Application Menu

The application menu appears in all MIDI Through windows. It contains items that let you display an incredibly boring About Box, open this online help, and quit the application.

The current port connection settings are saved whenever you quit MIDI Through.

MIDI Menu

The MIDI menu's single item, Panic, does the same thing the Panic button in the main window does. The keyboard shortcut for this command is Alt-Space.

Notes

Changes in this latest revision:

• Remember and restore the two windows' positions. Thanks to Jon Watte for his libprefs library.
• The application menu (to the left of the MIDI menu) now displays the application icon.
• The BeOS internal MIDI synth is initialized in a separate thread. What does this mean to you? Quicker startup times.

When playing the internal MIDI synth, there is a horrible delay. Jon Watte says, "The culprit is the Audio Kit. It has a minimum latency of one buffer, which is about 25 ms; typically you'll see latencies two or three times that number. This is a function of the BeBox hardware, and there's nothing you can do about it"

The number of MIDI in and out ports that MIDI Through handles is currently fixed. There is no way for the program to find out how many MIDI in and out ports your computer has.

I can't figure out how to get an application to exclusively launch, i.e., only launch one copy even if you double-click its icon more than once. So...don't do that!

I hate the pseudo-word "thru."