What is packet writing (a/k/a DLA – Drive Letter Access)?
(2002/05/28) Packet writing is an alternative to writing entire tracks or discs. It allows you to write much smaller chunks, down to the level of individual files. With track-at-once recording there’s a maximum of 99 tracks per disc, a minimum track length of 300 blocks, and an additional 150 blocks of overhead for run-in, run-out, pregap, and linking. Packet writing allows many writes per track, with only 7 blocks of overhead per write (4 for run-in, 2 for run-out, and 1 for link). Since it’s possible to write packets that are small enough to fit entirely in the CD recorder’s buffer, the risk of buffer underruns can be eliminated. There are some problems with packet writing, mostly due to the inability of older CD-ROM drives to deal with the gaps between packets. CD-ROM drives can become confused if they read into the gap, a problem complicated by read-ahead optimizations on some models.
Packet writing is an alternative to writing entire tracks or discs. It allows you to write much smaller chunks, down to the level of individual files. With track-at-once recording there’s a maximum of 99 tracks per disc, a minimum track length of 300 blocks, and an additional 150 blocks of overhead for run-in, run-out, pregap, and linking. Packet writing allows many writes per track, with only 7 blocks of overhead per write (4 for run-in, 2 for run-out, and 1 for link). Since it’s possible to write packets that are small enough to fit entirely in the CD recorder’s buffer, the risk of buffer underruns can be eliminated. There are some problems with packet writing, mostly due to the inability of older CD-ROM drives to deal with the gaps between packets. CD-ROM drives can become confused if they read into the gap, a problem complicated by read-ahead optimizations on some models. There are two basic “philosophies” behind packet writing, fixed-size and variable-size. With fixed-size packets
(2002/05/28) Packet writing is an alternative to writing entire tracks or discs. It allows you to write much smaller chunks, down to the level of individual files. With track-at-once recording there’s a maximum of 99 tracks per disc, a minimum track length of 300 blocks, and an additional 150 blocks of overhead for run-in, run-out, pregap, and linking. Packet writing allows many writes per track, with only 7 blocks of overhead per write (4 for run-in, 2 for run-out, and 1 for link). Since it’s possible to write packets that are small enough to fit entirely in the CD recorder’s buffer, the risk of buffer underruns can be eliminated. There are some problems with packet writing, mostly due to the inability of older CD-ROM drives to deal with the gaps between packets. CD-ROM drives can become confused if they read into the gap, a problem complicated by read-ahead optimizations on some models. There are two basic “philosophies” behind packet writing, fixed-size and variable-size. With fixed
