IBM System/370 145 Manual page 134

A data security erase command is provided for the 3410/3411. This
command is not provided for 2400-series tape drives. When a data
security erase command is issued, the tape unit selected erases tape
from the point at which the operation is initiated until the tape
indicate (end-of-file) marker is sensed.
The 3410/3411 tape subsystem has many of the reliability,
availability, and serviceability features offered by the 3803/3420
subsystem. Phase-encoded recording and radial tape unit attachment have
already been mentioned. (Phase-encoded recording is explained in
section 20:25.) The 3411, like the 3803, also uses digital signals,
instead of analog, to transfer data across the I/O interface, which
increases SUbsystem reliability by reducing its sensitivity to noise
caused by power fluctuations. static, etc.
The tape control portion of the 3411 is implemented in monolithic
technology and is a smaller version of the 3803 control unit that offers
many of the same advantages of 3803 technology. The 3411 provides more
sense bytes than the 2400-series tape units (nine instead of six) and
improved serviceability via microdiagnostics contained in the control
unit. Tape motion microprograms can be executed by the customer
engineer when the 3411 is switched to offline status.
Table 20.27.1 compares the features of 3410, 241~, and 2401 tape
units.
In summary, users of 2401 Models 1, 2, and 4 and 2415 tape units will
find the 3410/3411 tape subsystem offers the following advantages:
• Improved price performance
• Minimized floor space requirements
• Simplified tape threading and a push-pull hub to minimize tape setup
time
• Improved
RAS
features
• compatibility with 2400- and 3400-series tape units
124 A Guide to the IBM System/370 Model 145