Pioneer MJ-D508 - Manual (Page 9)

____ About the Table of Contents
When you load any kind of nninidisc into the recorder, the
first thing it does is read a section of the disc called the
Table of Contents, or TOC. Just as the contents page of a
book tells the reader what each chapter is about and
where to find it in the book, the TOC tells the recorder
where the tracks are on the disc, the name and length of
each track, the name of the disc, and so on. in the couple
of seconds it takes to read all this, the recorder's display
shows the message TOC Reading.
Since you can change what's on a recordable MD, the
Table of Contents is rewritable, and so is called the User
Table of Contents, or UTOC for short. If you have a
recordable disc loaded in the recorder and hit eject, the
recorder automatically updates the UTOC before giving you
the disc back. Alternatively, you can have the recorder
update the UTOC at any time using the UTOC write
function. In both cases, the message UTOC Writing
appears in the display during the UTOC updating process.
The UTOC is vital for the recorder to be able to play a disc
correctly. Until you hit eject or perform a UTOC write
command, the recorder stores all the current session's
recording and editing information in its memory. If there's a
power failure or you accidently switch the recorder off
before it's had a chance to write the UTOC there's a danger
that all that disc information will be lost. To prevent this,
switch the recorder back on as soon as possible and eject
the disc, if you leave the unit off for a week or more, the
information stored in the memory will be permanently lost
and the recordings/edits on that disc lost.
____ About MD System Limitations
The sophisticated playback, editing and recording features
available to you with MD are possible because of the way
in which the sound data is stored on the disc together
with the system of TOCs and UTOCs described above.
There are times however when you might encounter odd
side-effects of the way the system works. These are not
malfunctions, but limitations of the system. Below is a list
of symptoms you may run across depending on the way
you record or edit discs.
Symptom MD System Limitation
The recorder shows the message
TOC full even though there are fewer
than 255 tracks on the disc (the
maximum possible).
The recorder shows the message Disc
full before you've reached the maxi­
mum recording time of the disc.
The amount of recording time available
doesn't increase after erasing some
short tracks.
The total recorded time, plus the
recording time remaining, appears to be
less than the length of the disc.
The recorder won't allow you to
combine two tracks into one during
editing.
The sound is interrupted during fast
forward or reverse.
Although when you listen to a disc it appears that each track sits end to end in an
unbroken sequence, the actual audio information may be scattered all over the disc in
different places. The more times you record and edit things on a disc, the more
scattered the information becomes. Usually, this doesn't affect the user; the recorder
keeps track of everything using the UTOC. However, because the recorder needs to
know where every little gap is on the disc (and counts each one as a track, although
you don't see it), the UTOC eventually fills up, and the recorder won't let you record
anything else on that disc. Erasing a complete track, or the entire disc cures the
problem.
If a disc is scratched or damaged in some way, that part of the disc becomes auto­
matically unavailable for recording. In this case, the recorder shows the reduced
recording time available.
If you erase a track which is less than 12 seconds long, the recorder can't add that
time to the available recording time.
Recording time on a disc is divided into two second blocks—^the smallest 'unit' of a
minidisc. Although a piece of audio data may be shorter than this, it still takes up two
seconds on the disc, and the remainder is 'lost' (until the whole block is erased). As
the number of these partially used blocks builds up, you might notice that the total
disc length appears to shorten. (See also the note about damaged discs above.)
There are two situations where you can't use the combine edit feature:
❖ When one of the tracks was recorded using the digital input, and the other using
the analog input.
❖ When one track was recorded in long-play mono mode, and the other in normal
stereo mode.
As we mentioned above, the more re-recording and editing you do on a disc, the
more scattered the audio information on the disc becomes. During fast forward or
reverse this may show up as interrupted sound.
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