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FASTRAND was a magnetic drum mass storage system built by Sperry Rand Corporation (later Sperry Univac) for their UNIVAC 1100 series and 418/490/494 series computers. A FASTRAND subsystem consisted of one or two Control Units and up to eight FASTRAND units. A dual-access FASTRAND subsystem included two complete control units, and provided parallel data paths that allowed simultaneous operations on any two FASTRAND units in the subsystem. Each control unit interfaced to one (optionally two) 1100 Series (36-bit), or 490 Series (30-bit), parallel I/O channels.
A voice coil actuator moved a bar containing multiple single track recording heads, so these drums operated much like moving head disk drives with multiple disks. The heads "flew" on self-acting hydrodynamic air bearings. The drums had a plated magnetic recording surface. An optional feature called Fastband included 24 additional tracks with fixed read/write heads. This feature provided rapid access (35 ms. average access time), and a write lockout feature.
The Fastrands were very heavy (5,000 pounds) and large, approximately 8' long. Due to their weight, FASTRAND units were usually not installed on "false floor", and required special rigging and mounts to move and/or install. There were reported cases of drum bearing failures that caused the machine to tear itself apart and send the heavy drum crashing through walls.
At the time of their introduction the storage capacity exceeded any other random access mass storage disk or drum.
There were three models of FASTRAND drives:
Storage capacity: 22,020,096 36-bit words = 132,120,576 6-bit FIELDATA characters = 99 megabytes (8-bit bytes) per device
Drum rotation rate: 880 RPM (14.7 rotations per second)
Heads: 64
Sector size: 28 36-bit words
Track size: 64 sectors (1,792 36-bit words)
Track density: 105 tracks per inch
Average Access time (seek time plus rotational latency): 92 milliseconds
Data transfer rate: 26,283 36-bit words per second = 118 kilobytes per second (8-bit bytes) on 1100 series machines
Recording density, one-dimensional: 1,000 bits per inch (along one track)
Recording density, two-dimensional: 105,000 bits per square inch of drum surface
Max FASTRAND devices (drum units) per controller: 8
Controller price: $41,680 (1968 US dollars)
FASTRAND device price: $134,400 (1968 dollars, equivalent to $1.13 million in 2022 dollars)
Weight per FASTRAND device: 4,500 pounds
Weight per kilobyte: 6 ounces (170 g)
Despite the name, FASTRAND was slow. The head positioning time was significant, so software allocated storage by tracks (1,792 words, 10,752 characters or 8,064 eight-bit bytes) or "positions", a group of 64 tracks (114,688 words, 688,128 characters or 510,096 eight-bit bytes) which were under the heads at a single time. This storage allocation method remained on the 1100 series machines long after drums had been replaced by disks.
The track storage units were checkboarded so that, with precise computation of the program's processing time, one could create software with processing time per unit of Fastrand blocks that resulted in a program running in synchronism with the data transfer rate of the drum. Further, the track-to-track head movement time afforded an additional processing speed coordination possibility that permitted the computational rate to match the data transfer rate for large (for the time) data sets without being delayed by losing synchronism with the mass storage transfers.
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A binary prefix is a unit prefix that indicates a multiple of a unit of measurement by an integer power of two. The most commonly used binary prefixes are kibi (symbol Ki, meaning 210 = 1024), mebi (Mi, 220 = 1048576), and gibi (Gi, 230 = 1073741824). They are most often used in information technology as multipliers of bit and byte, when expressing the capacity of storage devices or the size of computer files.
Disk storage is a general category of storage mechanisms where data is recorded by various electronic, magnetic, optical, or mechanical changes to a surface layer of one or more rotating disks. A disk drive is a device implementing such a storage mechanism. Notable types are today's hard disk drives (HDD) containing one or more non-removable rigid platters, the floppy disk drive (FDD) and its removable floppy disk, and various optical disc drives (ODD) and associated optical disc media.
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 magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box.
The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applications and a complete range of applications from small to large. The design distinguished between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the only partially compatible Model 44 and the most expensive systems use microcode to implement the instruction set, featuring 8-bit byte addressing and binary, decimal and hexadecimal floating-point calculations.
The Honeywell 6000 series computers were rebadged versions of General Electric's 600-series mainframes manufactured by Honeywell International, Inc. from 1970 to 1989. Honeywell acquired the line when it purchased GE's computer division in 1970 and continued to develop them under a variety of names for many years. In 1989, Honeywell sold its computer division to the French company Groupe Bull who continued to market compatible machines.
UNIVAC was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company and successor organizations.
Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory.
The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Series. The solid-state 1107 model number was in the same sequence as the earlier vacuum-tube computers, but the early computers were not compatible with the solid-state successors.
In computer science, group coded recording or group code recording (GCR) refers to several distinct but related encoding methods for representing data on magnetic media. The first, used in 6250 bpi magnetic tape since 1973, is an error-correcting code combined with a run-length limited (RLL) encoding scheme, belonging into the group of modulation codes. The others are different mainframe hard disk as well as floppy disk encoding methods used in some microcomputers until the late 1980s. GCR is a modified form of a NRZI code, but necessarily with a higher transition density.
IBM manufactured magnetic disk storage devices from 1956 to 2003, when it sold its hard disk drive business to Hitachi. Both the hard disk drive (HDD) and floppy disk drive (FDD) were invented by IBM and as such IBM's employees were responsible for many of the innovations in these products and their technologies. The basic mechanical arrangement of hard disk drives has not changed since the IBM 1301. Disk drive performance and characteristics are measured by the same standards now as they were in the 1950s. Few products in history have enjoyed such spectacular declines in cost and physical size along with equally dramatic improvements in capacity and performance.
In computer storage, zone bit recording (ZBR) is a method used by disk drives to optimise the tracks for increased data capacity. It does this by placing more sectors per zone on outer tracks than on inner tracks. This contrasts with other approaches, such as constant angular velocity (CAV) -drives, where the number of sectors per track are the same. On a disk consisting of roughly concentric tracks – whether realized as separate circular tracks or as a single spiral track – the physical track length (circumference) is increased as it gets farther from the centre hub.
The UNIVAC 1050 was a variable word-length decimal and binary computer. It was initially announced in May 1962 as an off-line input-output processor for larger UNIVAC systems.
The Massbus is a high-performance computer input/output bus designed in the 1970s by Digital Equipment Corporation (DEC). The architecture development was sponsored by Gordon Bell and John Levy was the principal architect.
In computer disk storage, a sector is a subdivision of a track on a magnetic disk or optical disc. For most disks, each sector stores a fixed amount of user-accessible data, traditionally 512 bytes for hard disk drives (HDDs) and 2048 bytes for CD-ROMs and DVD-ROMs. Newer HDDs and SSDs use 4096-byte (4 KiB) sectors, which are known as the Advanced Format (AF).
Count key data (CKD) is a direct-access storage device (DASD) data recording format introduced in 1964, by IBM with its IBM System/360 and still being emulated on IBM mainframes. It is a self-defining format with each data record represented by a Count Area that identifies the record and provides the number of bytes in an optional Key Area and an optional Data Area. This is in contrast to devices using fixed sector size or a separate format track.
This timeline of binary prefixes lists events in the history of the evolution, development, and use of units of measure which are germane to the definition of the binary prefixes by the International Electrotechnical Commission (IEC) in 1998, used primarily with units of information such as the bit and the byte.
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium encased in a rectangular plastic carrier. It is read and written using a floppy disk drive (FDD). Floppy disks were an almost universal data format from the 1970s into the 1990s, used for primary data storage as well as for backup and data transfers between computers.
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time .
In addition to the drums used as main memory by IBM, e.g., IBM 305, IBM 650, IBM offered drum devices as secondary storage for the 700/7000 series and System/360 series of computers.
A track is a path on a recording medium. There are some variations in nomenclature; for some media a track is a logical path and for others it is based on the geometry of the medium. The term is not used for punched cards.