A new addition to the Philips “intelligent drive” features,

Seamless Link acts to manage and minimise

the effects of buffer under run (BUR), a common cause

of wasted discs during the CD writing process.

Today, burning discs with a CD writer has become a common method of storing and
distributing data, text, video and audio files for PC users. With advances in writer speeds
and performance, greater ease of use, improved writing application software with
drag-and-drop functionality, and simple Graphical User Interfaces (GUI),
users today require less time and hassle when burning their first disc.
Other advances in CD writing are related to write integrity, and ensuring optimal writing
on nearly all media, as example, with Philips Thermo Balanced Writing (TBW) and Self
Learning strategies.
However, even with exponential strides in ease of use, and a mainstream place in new PC
systems for CD writers, users, especially those with older systems, still face an occasional
buffer under run error message. A less frequent error for users of new PC systems,
BUR is still an annoying problem.
While first addressing the problem via a software solution (Ultra-Buffer in co-operation
with AHEAD), Philips now takes the solution a step further, by placing the solution
on board the CD writer. For both users of new and older systems, Philips Seamless Link
on board offers an excellent management solution for BUR without tying users to a
specific application software provider.

INTRODUCTION

The Seamless Link algorithm (Fig. 4), constantly monitors the writer buffer level. If the writer buffer level
drops below a threshold value, the algorithm concludes that a BUR is imminent and stops the writing process
in a controlled way. This means that the data stream from the buffer to the disc is halted, and allows the
buffer to be filled up again.
The exact location where the writing stopped is stored in the drives internal memory. In the meantime,
the buffer level is continuously monitored and as soon as the buffer is full again, the algorithm will let the
drive seek to the location where the writing stopped. It then resumes the writing process as soon as the laser
is on the exact spot where the writing stopped. This type of writing eliminates the gap, which occurs between
two individual writing operations during traditional writing. Hence the name Seamless Link.

HOW SEAMLESS LINK WORKS

Fig. 4, The Seamless Link algorithm:
Seamless Link offers excellent management of BUR incidents when writing CD discs in Track-at-Once (TAO)
or Disc-at-Once (DAO) mode. By utilising the Seamless Link algorithm to monitor the CD writer buffer,
chances of a ruined or wasted disc are made remote.
In addition, Seamless Link gives end users greater confidence in running other applications during the CD
writing process, AND freedom from the time and frustration of retries due to a buffer under run incident.

SUMMARY

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