
25.4 Data Buffering
The CTS provides two modes of operation for the WRITE command:
unbuffered and buffered. The mode of operation is set with the
MODE SELECT command (byte 02, bits 6 through 4, in the Parameter
List Header).
Unbuffered Write Operation
When the CTS is set for an unbuffered write operation, it returns
Good status as soon as all data blocks are written to tape.
Buffered Write Operation
When the CTS is set for a buffered write operation, it returns Good
status as soon as all data blocks are successfully transferred to the
buffer. The data in the buffer is written to tape when one of the
following conditions occurs:
The motion threshold is reached during a WRITE command (see
Section 3.6).
The CTS receives one of the following commands:
•
REWIND (01h)
•
WRITE FILEMARKS (10h) non-immediate
•
SPACE (11h) in either direction
•
ERASE (19h)
•
LOAD/UNLOAD (1Bh)
•
LOCATE (2Bh) in the reverse direction
The operator presses the unload button.
The time specified for the Write Delay Time field in the MODE
SELECT command elapses (note, however, if the Write Delay
Time field is 0, a partially full buffer is not flushed to tape). See
Section 10.12 for more information about the Write Delay Time
field.
May 1994 EXB-8205 and EXB-8505
(Standard and XL)
25-5
25 WRITE (0Ah)
Kommentare zu diesen Handbüchern