LOGICAL BLOCK ADDRESSING

Domain	Definition
Computing	Logical Block Addressing (LBA) A hard disk sector addressing scheme used on all SCSI hard disks, and on ATA-2 conforming IDE hard disks. The addressing conversion is performed by the hard disk firmware. Prior to LBA, combined limitations of IBM PC BIOS and ATA restricted the useful capacity of IDE hard disks on IBM PCs and compatibles to 1024 cylinders * 63 sectors per track * 16 heads * 512 bytes per sector = 528 million bytes = 504 megabytes. Modern BIOSes select LBA mode automatically, and work around the 1024-cylinder BIOS limit by representing a hard disk to the OS as having e.g. half as many cylinders and twice as many heads. However, there is still an unbreakable BIOS disk size limit of 1024 cylinders * 63 sectors per track * 256 heads * 512 bytes per sector = 8 gigabytes, but modern OSes (including Windows 9x, Windows NT and Linux) are not affected by it, since they issue direct LBA-based calls, bypassing the BIOS hard disk services completely. (2000-04-30). Source: The Free On-line Dictionary of Computing.
Source: compiled by the editor from various references; see credits.

Hexadecimal (or equivalents, 770AD-1900s) (references)

Leonardo da Vinci (1452-1519; backwards) (references)

Binary Code (1918-1938, probably earlier) (references)

HTML Code (1990) (references)

ISO 10646 (1991-1993) (references)

Encryption (beginner's substitution cypher): (references)

Expression	Frequency per Day
logical block addressing	5
Source: compiled by the editor from various references; see credits.

Specialty Definition: LOGICAL BLOCK ADDRESSING