Quantum Audio Travan 40 Tape Drive STT3401A - Manual (Page 11)

Introduction Chapter 1
Seagate Travan 40 Product Manual Page 3
Figure 3
Sample ATAPI configurations
Minicartridge technology overview
Having evolved from the original mass-storage medium—reel-to-reel, one-half-inch
tape storage—the minicartridge technology of today offers fast, efficient, high-
capacity storage in a compact, easily-removable hard-shell package. In little more
than a decade, storage capacities have increased from some 60 megabytes
(Mbytes) on 9 tracks (QIC-24, 1982) to the 40-Gbyte (compressed) capacity
achievable with a single Travan 40 cartridge.
The streaming-tape intelligence in the Travan drive provides a continuous tape
motion with an uninterrupted, precisely coordinated flow of data to and from the
minicartridge. This "streaming" motion combined with the "serpentine" recording
method is one element that contributes to the increased storage capacities,
efficiency, and speed of today's minicartridge technology.
Use of the "serpentine" recording method exploits the bi-directional capabilities of the
cartridge. With this method, the tape is not rewound at the end of a track. Instead,
the write-read heads are logically or mechanically switched to a different position on
the tape and another track is written or read in the reverse direction. That is, the
drive first records track 1 in one direction and when the end of the tape is reached,
the head is moved and the direction of tape motion is reversed to record track 2.
This serpentine process continues until the entire tape is recorded. The individual
tracks are sequential to minimize the amount of head motion as the heads change
position for each track.