M-AUDIO MIDISPORT 8x8/s - Manual (Page 40)

the same IRQ. Another possibility is a driver associated with another device
used on the same serial port is adversely affecting the IRQ. Yet one more
possibility is that your serial port IRQ is disabled in your computer’s BIOS
CMOS setup, and simply needs to be switched on.
If you are unsure what your port IRQ is or how to find out, please see the section
in this manual titled “Selecting a Host Serial Port,” or consult your computer
owner’s manual or computer manufacturer directly.
5. SMPTE I/O Test
This test makes sure that the SMPTE In and Out jacks are functioning properly.
If this test fails, make sure that the cable you have looped from SMPTE In to
SMPTE Out is good, and also properly connected.
SMPTE/MIDI Time Code Tutorial
This section gives a brief tutorial on various SMPTE topics. This section is not by
any stretch of the imagination an exhaustive treatment of time code or syncing.
Instead, it is included to make the MIDISPORT 8x8/s SMPTE functions more
understandable.
What is SMPTE (Time Code)?
SMPTE is a time coding standard, which was developed in 1967 by the Society of
Motion Picture and Television Engineers (SMPTE) to be used in video editing.
SMPTE attaches a unique time stamp (80 bits of information) to each frame of
video or film. SMPTE readers may then extract that time information and
synchronize other devices to it. Because SMPTE may be encoded as an actual
audio signal, it also lends itself to audio applications and can be read from audio
tracks for synchronization purposes..
The SMPTE Time Code consists simply of: Hours : Minutes : Seconds : Frames.
Therefore a typical SMPTE time code reading would be: 01 : 25 : 42 : 17, which
represents the time 1 hour : 25 minutes : 42 seconds : 17 frames.
The original SMPTE Time Code was Longitudinal Time Code (LTC).
“Longitudinal” means that the code is laid down in a continuous audio stripe
along the length of the tape (longitudinally). The MIDISPORT 8x8/s is designed
to write this longitudinal time code (LTC) as well as read and convert it to MIDI
Time Code (MTC).
What is MIDI Time Code (MTC)?
MIDI Time Code (MTC) is the MIDI implementation of SMPTE. MTC was first
standardized in 1987 as a method of synchronizing MIDI software and hardware
sequencers, as well as drum machines. Later it was also adopted by digital audio
recording software and hardware manufacturers as a method of synchronizing
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