It allows programs to read and write logical records within physical blocks of data, as opposed to the less advanced Basic sequential access method ( BSAM ) which allows programs to access physical blocks of data, but provides no support for accessing logical records within blocks.
12.
Unlike the traditional fixed block systems, in the modern moving block CBTC systems the protected section for each train is not statically defined by the infrastructure ( except for the virtual block technology, with operating appearance of a moving block but still constrained by physical blocks ).
13.
"' Write Ahead Physical Block Logging "'( WAPBL ) provides meta data journaling for file systems in conjunction with Fast File System ( FFS ) to accomplish rapid filesystem consistency after an unclean shutdown of the filesystem and better general use performance over regular FFS.
14.
:Most modern flash memory controllers incorporate wear levelling into the flash controller, wherein there is a lookup table that maps logical block addresses with physical block addresses, and the PBA for a given LBA is shuffled around ( on erase ) ( example ( pdf ) ).
15.
In the DD statement, the BLKSIZE is specified as a non-zero value and this, then, results in a program-specified LRECL ( logical record length ) and a JCL-specified BLKSIZE ( physical block size ), with the merge of the two becoming the permanent definition of the dataset.
16.
It is a gate level model of a physical block where only the connections from the inputs to the first stage of flip-flops, and the connections from the last stage of flip-flops to the outputs are in the model, including the flip-flops and the clock tree driving these flip-flops.
17.
If the dataset is unblocked, that is, the logical record length ( LRECL ) is equal to the physical block size ( BLKSIZE ), BSAM may be utilized to simulate a directly accessed dataset using NOTE and POINT on any supported direct access device type ( DEVD = DA ), and some primitive applications were designed in this way.
