HP Q1581A HP DDS/DAT drives UNIX, Linux and OpenVMS configuration guide (DW049 - Page 39
Glossary, functionality. In AT&T - specification
![]() |
UPC - 882780612716
View all HP Q1581A manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 39 highlights
Glossary AT&T mode Berkeley mode block BOP buffered mode compression DAT data transfer phase Berkeley and AT&T functional modes differ in "read-only" close functionality. In AT&T mode, a device close operation will cause the tape to be repositioned just after next filemark on the tape (the start of the next file). Berkeley and AT&T functional modes differ in "read-only" close functionality. In Berkeley mode the tape position will remain unchanged by a device close operation. A logical unit of information. Called "record" in the DDS-format specification. Beginning Of Partition. The position at the beginning of the permissible recording region of a partition. A mode of data transfer in write operations that facilitates tape streaming. A procedure in which data is transformed by the removal of redundant information in order to reduce the number of bits required to represent the data. This is done by representing strings of bytes with codewords. Digital Audio Tape On a SCSI bus, devices put in requests to be able to transfer information. Once a device is granted its request, it and the target to which it wants to send information can transfer the data using one of three protocols (assuming both devices support them): asynchronous, synchronous, and wide. In asynchronous transfers, the target controls the flow of data. The initiator can only send data when the target has acknowledged receipt of the previous packet. All SCSI devices must support asynchronous transfer. In synchronous data transfer, the initiator and target work in synchronization, allowing transmission of a packet of data to start before acknowledgment of the previous transmission. In wide (16-bit) data transfer, two bytes are transferred at the same time instead of a single byte. HP DDS/DAT drives support asynchronous, synchronous and narrow (8-bit) wide transfers. HP Evolution II DDS/DAT drives: UNIX, Linux and OpenVMS configuration guide 39
![](/manual_guide/products/hewlettpackard-c5686c-hp-ddsdat-drives-unix-linux-openvms-configuration-guide-dw04990915-2009-70f504d/39.png)