In computing, a rigid disk block (RDB) is the block on a

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...

where the

Amiga Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...

series of computers store the disk's partition and filesystem information. The IBM's PC equivalent of the Amiga's RDB is the

master boot record A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBR ...

(MBR). Unlike its PC equivalent, the RDB doesn't directly contain metadata for each partition. Instead it points to a

linked list In computer science, a linked list is a linear collection of data elements whose order is not given by their physical placement in memory. Instead, each element points to the next. It is a data structure consisting of a collection of nodes whic ...

of partition blocks, which contain the actual partition data. The partition data includes the start, length, filesystem, boot priority, buffer memory type and "flavor", though the latter was never used. Because there is no limitation in partition block count, there is no need to distinguish primary and extended types and all partitions are equal in stature and architecture. Additionally, it may point to additional filesystem drivers, allowing the Amiga to boot from filesystems not directly supported by the ROM, such as PFS or SFS. The data in the rigid disk block must start with the

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

bytes "RDSK". Furthermore, its position is not restricted to the very first block of a volume, instead it could be located anywhere within its first 16 blocks. Thus it could safely coexist with a master boot record, which is forced to be found at block 0. Nearly all Amiga hard disk controllers support the RDB standard, enabling the user to exchange disks between controllers.

External links

The .ADF (Amiga Disk File) format FAQ; 6. The structure of a hard disksPrints out information stored in RigidDiskBlocks of any device
including source Amiga AmigaOS MorphOS Booting Disk partitions {{Compu-hardware-stub

See also

External links