Jump to content

IBM 1302

From Alfawiki
IBM
IndustryComputer hardware, data storage
FoundedJune 16, 1911; 115 years ago (1911-06-16)
Headquarters
Armonk, New York
,
United States
ProductsHard disk drives, floppy disk drives, computer hardware
Websitewww.ibm.com

IBM was a pioneer in producing magnetic disk storage devices from 1956 until 2003, at which point it divested its hard disk drive division to Hitachi. The company is credited with inventing both the hard disk drive (HDD) and the floppy disk drive (FDD), with numerous technological advancements driven by IBM’s engineers. The fundamental mechanical architecture of hard disk drives has remained largely unchanged since the introduction of the IBM 1301, and performance benchmarks have adhered to consistent standards dating back to the 1950s. Over time, these storage devices have experienced significant decreases in size and cost, accompanied by substantial enhancements in capacity and speed.

IBM manufactured 8-inch floppy disk drives from 1969 through the mid-1980s; however, it did not become a leading producer of the smaller 5.25-inch or 3.5-inch formats. While IBM consistently sold its magnetic disk drives, it only began providing them under original equipment manufacturer (OEM) agreements starting in 1981. By 1996, IBM had discontinued producing HDDs exclusive to its own systems, transitioning entirely to OEM offerings.

Throughout its history, IBM referred to its magnetic disk drives using terms such as direct-access storage device (DASD), disk file, and diskette file. For clarity, this article employs the widely accepted industry terminology: hard disk drive (HDD) and floppy disk drive (FDD).

IBM 350

The IBM 350 disk storage unit holds the distinction of being the first commercial disk drive, introduced by IBM on September 14, 1956, as part of the IBM 305 RAMAC system. A related model, the IBM 355, was launched for use with the IBM 650 RAMAC system. The initial prototype was delivered to Zellerbach Paper Company in June 1956, while production units began shipping in November 1957 to clients such as United Airlines.

Engineered for real-time business accounting applications, the IBM 350 had a storage capacity of five million six-bit characters (equivalent to 3.75 MB). It consisted of fifty-two disks measuring 24 inches in diameter, utilizing one hundred recording surfaces spinning at a rate of 1200 revolutions per minute. The data transfer speed reached 8,800 characters per second. Its access mechanism enabled read/write heads to move across selected disk pairs and tracks. Several enhanced versions were released throughout the late 1950s. Leasing costs for the IBM RAMAC 305 system with the 350 disk file were approximately $3,200 monthly. Production of the IBM 350 concluded in 1969.

US Patent 3,503,060, originating from the RAMAC development program, is recognized as a foundational patent for disk drive technology. Despite initial cancellation by IBM’s Board due to concerns over potential negative impact on punch card operations, development persisted at IBM’s San Jose facility until receiving approval from IBM’s president.

The physical dimensions of the unit were substantial: approximately 60 inches long, 68 inches tall, and 29 inches wide, with a weight close to one ton—requiring forklift equipment for relocation. Currie Munce of Hitachi Global Storage Technologies (the successor to IBM’s storage division) noted that although capacity could have been extended beyond five million characters, marketing hesitated due to uncertainty about market demand. Nevertheless, versions with double capacity were announced in January 1959 and shipped later that year.

In recognition of its significance, the RAMAC 350 Disk File was designated an International Historic Landmark by The American Society of Mechanical Engineers in 1984. Starting in 2002, a restoration initiative led by Al Hoagland, in collaboration with Santa Clara University, worked on refurbishing an IBM 350 RAMAC unit. In 2005, this restored system was moved to the Computer History Museum, where it remains on public display as part of the Revolution exhibition.

IBM 353

The IBM 353, implemented on the IBM 7030, resembled the IBM 1301 but offered a higher data transfer speed. It provided storage for 2,097,152 (221) 64-bit words, equivalent to 134,217,728 bits, and achieved a transfer rate of 125,000 words per second. A prototype delivered in late 1960 was notable as the first disk drive to employ a dedicated head per surface that floated on compressed air, a concept akin to the IBM 350 design. Production models featured self-levitating heads nearly identical to those utilized in the IBM 1301.

IBM 355

Introduced on September 14, 1956, the IBM 355 served as an enhancement for the widely used IBM 650. It incorporated the IBM 350 mechanism but included up to three access arms instead of one, allowing it to store six million decimal digits plus an additional 600,000 sign characters. Data transfer involved moving an entire track between the magnetic core memory of the 653—an optional IBM 650 component holding sixty signed 10-digit words—and the storage device. This unit also supported two other unrelated functions.

IBM 1405

Announced in 1961 for the IBM 1400 series business computers, the IBM 1405 Disk Storage Unit was available in two variants: Model 1 held 10 million alphanumeric characters (60 million bits) across 25 disks, while Model 2 doubled this capacity with 20 million characters (120 million bits) spread over 50 disks. The disks were arranged vertically and rotated at a speed of 1200 rpm.

Each disk surface contained 200 tracks subdivided into five sectors; sectors numbered 0 through 4 were located on top surfaces, with sectors 5 through 9 on bottom surfaces. Sector capacity ranged from 178 to 200 characters. Between one and three forked access arms were equipped with two read/write heads each—one for the top and one for the bottom side of a disk. These arms moved vertically to select among disks numbered from 0 to 49 and horizontally to position over tracks numbered from 0 to 199. Each track comprised ten sectors, with read/write operations taking approximately 10 milliseconds per sector.

Access times varied between a minimum of about 100 milliseconds and a maximum of up to 700 milliseconds for Model 1 and up to 800 milliseconds for Model 2. The Model 2 unit contained around 100,000 sectors capable of holding either 200 characters in move mode or slightly fewer (178) in load mode, which incorporated an additional word mark bit per character. Model 1 had approximately half that number of sectors.

IBM 7300

Designed specifically for use with the IBM 7070, the IBM 7300 Disk Storage Unit had a second model announced in 1959. However, following the introduction of the IBM 1301 on June 5, 1961, customers using the IBM 7070 and IBM 7074 found the latter more appealing. The technology employed in the IBM 7300 was consistent with that found in earlier models such as the IBM 350, IBM 355, and IBM 1405.

IBM 1301

Unveiled on June 2, 1961, the IBM 1301 Disk Storage Unit was intended for use with mainframe computers in the 7000 series as well as with the IBM 1410. Each module stored up to twenty-eight million characters (twenty-five million when paired with the IBM 1410), utilizing twenty-five large disks with forty recording surfaces accessible to users and featuring two hundred fifty tracks per surface. The Model 1 configuration consisted of a single module; Model 2 stacked two modules vertically. Disks rotated at a speed of eighteen hundred revolutions per minute, enabling data transfers at ninety thousand characters per second.

A significant advancement was its use of an individual arm and read/write head dedicated to each surface that moved simultaneously in unison resembling a comb mechanism. This architecture eliminated delays caused by repositioning heads across multiple disks and lowered maximum access times to approximately one hundred eighty milliseconds. Additionally, it was pioneering in employing aerodynamically designed heads that hovered on a thin cushion of air above disk surfaces, improving operational efficiency.

Connection to host systems was facilitated by the IBM 7631 File Control unit, allowing compatibility with either an IBM 1410 or a IBM 7000 series computer or enabling shared operation between two machines.

Pricing for leasing an IBM 1301 Model 1 was $2,100 monthly or $115,500 for purchase; Model 2 rental cost $3,500 per month or $185,000 if bought outright. The IBM 7631 controller carried an additional monthly lease fee of $1,185 or $56,000 if acquired. All versions were discontinued by around the year 1970.

IBM 1302

Introduced in September 1963, the IBM 1302 Disk Storage Unit increased storage capacity fourfold compared to the IBM 1301, reaching 117 million 6-bit characters per module. It offered an average access time of 165 milliseconds and data transfer speeds of 180,000 characters per second, more than twice as fast as its predecessor. Each module incorporated two separate access mechanisms dedicated to the inner and outer cylinders. The Model 2 variant doubled the storage by stacking two modules together. Leasing fees were set at $5,600 per month for Model 1 and $7,900 per month for Model 2, while purchase prices stood at $252,000 and $355,500 respectively. The IBM 7631 controller was available for an additional monthly lease of $1,185 or a purchase price of $56,000. Production of the 1302 ceased in February 1965.

IBM 1311

The IBM 1311 Disk Storage Drive was announced on October 11, 1962, targeting mid-range business and scientific computer systems. Comparable in size to a top-loading washing machine, it utilized a removable IBM 1316 disk pack capable of storing two million characters. Throughout the 1960s, seven different models were released before being phased out in the early 1970s.

Each IBM 1316 disk pack measures roughly four inches in height, weighs around ten pounds, and contains six disks each measuring fourteen inches in diameter, providing ten usable recording surfaces. The disks rotate at 1500 revolutions per minute and employ ten read/write heads mounted on a hydraulic actuator that positions them precisely over tracks for reading or writing operations. Every surface includes 100 tracks with twenty sectors per track; each sector holds one hundred characters. The disk pack is enclosed within a transparent plastic shell with a bottom cover to facilitate handling.

Among the seven IBM 1311 models are master drives—equipped with controllers and additional power supplies—and slave drives that operate under master control. Master drives can manage multiple slave units across various IBM platforms including the IBM 1401, IBM 1410, IBM 1440, and IBM 1620. Differences among models include system compatibility and feature sets; generally, master drives are larger than their slave counterparts.

Several optional features were available to enhance drive performance:

  • Direct Seek: Removes the need to return to track zero prior to seeking.
  • Scan Disk: Enables fast automatic search operations.
  • Seek Overlap: Permits overlapping seek commands during simultaneous read/write activities on multiple drives.
  • Track Record: Boosts storage capacity by recording one large record per track instead of multiple sectors, increasing total capacity to approximately 17.9 million bits in 6-bit mode or 18.8 million bits in 7-bit mode.

Master drives (Models 1, 3, 4, and 5) include built-in control logic and extra power supplies, making these units roughly one foot wider than Model 2 slave drives.

IBM 2302

The IBM 2302 serves as the System/360 adaptation of the IBM 1302, featuring track formatting tailored to S/360 DASD standards. It employs a fixed module composed of twenty-five platters with forty-six recording surfaces. The Model 3 contains a single module, whereas Model 4 houses two modules stacked together. Each module is equipped with two independent access mechanisms—referred to as access groups—each responsible for managing up to 250 cylinders with one read/write head assigned per track. Rotational latency averages around seventeen milliseconds with a maximum delay of thirty-four milliseconds. The maximum seek time within each access group is approximately one hundred eighty milliseconds. Tracks hold up to 4,985 bytes each, resulting in an overall module capacity near one hundred twelve megabytes. Connectivity to IBM mainframes is facilitated through the IBM 2841 Storage Control Unit.

IBM 2305

Introduced in 1970, the IBM 2305 fixed-head storage drive, paired with the IBM 2835 Storage Control, initially connected to the 360/85 and 360/195 systems through the IBM 2880 Block Multiplexor Channel.

During the System/370 period, especially with Virtual Storage capabilities, the 2305 was widely utilized as a paging device across multiple systems such as the 3155, 3165, 3158, 3168, 3033, 4341, and 3081 (the latter requiring specialized microcode). It also efficiently handled small but frequently accessed data sets like catalogs and job queues.

The IBM 2305-1 model offered a storage capacity of 5.4 MB, delivering data at a rate of 3.0 MB/s and an average access latency of 2.5 milliseconds. In contrast, the larger 2305-2 variant provided an 11.2 MB capacity with a throughput of 1.5 MB/s and an average seek time of 5 milliseconds.

Combining substantial storage space with high-speed data transfer made the 2305 particularly suitable for system-resident tasks, including work files, job queues, indices, and other often-used datasets. Its rapid response time rendered it ideal as a paging device in environments processing more than 1.5 transactions per second under heavy workloads.

IBM 2311

The IBM 2311 Disk Storage Drive debuted in 1964 alongside the 2841 Control Unit, designed primarily for the IBM System/360 family but also compatible with the IBM 1130 and IBM 1800. It connects directly to models like the IBM System/360 Model 20 and Model 25. All units utilize removable IBM 1316 Disk Packs, which trace their origins back to the IBM 1311.

The Model 1 version interfaces with most IBM mainframes through the 2841 Control Unit; when attached to the System/360 Model 25, it uses a Disk Attachment Control that provides comparable functionality. Disk packs are formatted using IBM’s count key data variable-length record structure.

Models 11 and 12, which operate with the integrated control of the System/360 Model 20, adopt a fixed sector format. Due to these differing formats, disk packs are not interchangeable between Model 1 drives and Models 11 or 12.

Although mechanically akin to the IBM 1311, the IBM 2311 improved recording technology and offered a capacity of approximately 7.25 megabytes on a six-platter removable disk pack. The drive contains ten read/write heads mounted on a hydraulically actuated assembly featuring mechanical detents for precise track alignment. Each platter surface supports up to 200 tracks plus three spare tracks reserved for defect management. The average seek time is around 85 milliseconds with a data transfer speed of approximately 156 kB/s.

Uniform electrical interfaces across various System/360 models permitted third-party vendors to create plug-compatible disk drives, fostering a competitive market for storage devices compatible with IBM systems.

IBM 2314 Disk Access Storage Facility Model 1

Released in April 1965, the IBM 2314 Disk Access Storage Facility Model 1 was compatible with both System/360 and System/370 platforms. It featured a Two Channel Switch that allowed simultaneous connection to two separate channels. While its mechanism was similar to that of the IBM 2311, it provided significantly greater data density.

This model stored about twenty-nine million characters on a removable IBM 2316 disk pack, which expanded the number of platters from six to eleven, totaling twenty recording surfaces. The drive employed twenty read/write heads mounted on a hydraulically actuated mechanism equipped with mechanical detents for precise positioning. Each surface contained up to two hundred tracks. Initial access times were comparable to those of the IBM 2311 but were reduced in subsequent versions due to improvements in actuator technology. The data transfer rate doubled compared to its predecessor, reaching around 310 kB/s.

The Model 1 package included nine disk drives at a single price point: one storage control unit, one single-drive module, and two modules each containing four drives. These drives were installed in drawer-like assemblies for easy disk pack access—informally dubbed "Pizza Ovens." Although only eight drives could be accessed simultaneously, the ninth functioned as an offline spare allowing maintenance without interrupting operations. Drive system addresses were assigned via user-removable plugs that facilitated straightforward reassignment and spare designation.

An optional IBM 2844 Control Unit provided capability for two System/360 channels to concurrently access different drives within the storage facility.

Subsequent versions of the IBM 2314 were introduced later on, offering increased capacity and enhanced features.

IBM 2314 Direct Access Storage System - Series Overview

In 1969, IBM segmented the original facility into distinct models, each supporting up to nine drives (with eight accessible online) connected to a 2314 Storage Control. The lineup included:

  • 2312 Disk Storage, featuring a single-drive unit.
  • 2313 Disk Storage, equipped with four drives.
  • 2318 Disk Storage, comprising two drives.

IBM 2319

To address competition from plug-compatible manufacturers producing storage systems comparable to the 2314, IBM launched the more affordable three-drive 2319 series in 1970. This series originated by removing one drive from the four-drive 2313 module, rebranding the resulting unit as the 2319 A1, and offering it at a significantly lower rental cost. This strategy reduced expenses for new clients while preserving higher pricing for existing customers. The 2319-A1 connects to integrated controllers designed for System/370 Models 135 and 145. Additionally, traditional 2314 DASD units such as the 2312 or 2318 can be linked to the 2319-A1. The 2319 B series expanded support to configurations with three, six, or nine drives attached to a new 2314 Model B Storage Control Unit.

IBM 3310

On January 30, 1979, IBM introduced the IBM 3310 Direct Access Storage Device aimed at IBM 4331 midrange computer systems. Each drive provided a storage capacity of 64.5 MB. The 3310 utilized fixed-block architecture and was compatible with DOS/VSE and VM, which were the only S/370 operating systems supporting FBA devices.

IBM 3330

The IBM 3330 Direct Access Storage Facility, internally referred to as Merlin, debuted in June 1970 for use with IBM System/370 and System/360/195 systems. The initial offerings included a two-drive Model 1 and a single-drive Model 2. Removable disk packs held up to 100 MB each, delivering access times of approximately 30 ms and data transfer speeds of 806 kB/s. A notable innovation was the implementation of fire code error correction, enhancing reliability and lowering costs by compensating for disk surface flaws.

Originally, the configuration consisted of one storage control unit (3830 Model 1) mounted directly to a single 3330 drive, with the option to add up to three additional drives in a chain—allowing a maximum of eight drives per string.

In August 1972, IBM released the 3830 Model 2 Storage Control along with the 3333 Disk Storage and Control, which separated control functions from storage drives. The upgraded 3830 became a director-style controller capable of managing multiple strings simultaneously. The initial unit in each string, the 3333, incorporated both controller and two drives and could support up to three additional attached 3330s for a total of eight drives per string. Two such 3333 units could be connected to a single 3830 Model 2 controller, enabling support for as many as sixteen drives per controller. An optional string switch on the 3333 allowed connection to two separate controllers.

In 1973, IBM introduced double-density (-11) variants: the models designated as 3333–11, 3330-11, along with larger-capacity (200 MB) disk packs known as the 3336–11. Mixing single-density and double-density drives within the same string was not supported. Field upgrades from original models to Model-11 versions were possible but required converting existing drives and migrating data accordingly.

The IBM 3330 line was discontinued in 1983.

IBM 3340 and IBM 3344

The IBM 3340 and 3344 models share many characteristics; however, only the 3340 can function as the head of string. Notably, there are no A model versions of the 3344, and any 3344 must be connected to a 3340 A model acting as the head of string.

IBM 3340

Introduced in March 1973 for the IBM System/370, the IBM 3340 Direct Access Storage Facility bore the code name Winchester. It was available in three configurations: 3340-A2 (which included two drives with a controller), B2 (two drives without controller), and B1 (a single drive). The B units could be attached to an A2 unit, supporting up to eight drives in a chain.

This system utilized removable data modules that incorporated both the read/write heads and arm assemblies. Unlike previous disk packs, its access door opened during mechanical load and unload operations, removing the necessity to detach covers. The device offered an access time of 25 milliseconds and a data transfer rate of 885 kilobytes per second. Three types of IBM 3348 Data Modules were marketed: one with a capacity of 35 MB and two with 70 MB, one of which included a fixed-head section of 500 KB for faster access. The design integrated error correction features and remained in production until its withdrawal in 1984.

The development took place in San Jose under Ken Haughton’s leadership. The initial concept revolved around two removable modules each holding 30 MB, inspiring the Winchester code name after the Winchester .30-30 rifle. While storage capacities increased over time, the original nickname persisted.

A major breakthrough was the introduction of a cost-effective head design that eliminated the need to unload heads from media. This "Winchester technology" enabled read/write heads to land on and lift off from spinning disks, significantly simplifying and reducing expenses related to head and arm mechanisms. This approach became widely adopted throughout the hard disk industry.

The term Winchester or colloquially Winnie was commonly used to describe hard drives into the early 1990s but has since largely fallen out of use worldwide.

IBM 3344

The IBM 3344 closely resembles the 3340 but differs by employing fixed media instead of removable IBM 3348 data modules. Each spindle supports four logical drives, each matching the capacity of a single 70 MB IBM 3348 module. Available exclusively as dual-drive models, the 3344 does not include an A model capable of serving as head of string. The variant known as 3344-B2F incorporates fixed heads over certain cylinders on both drives. Both the 3344-B2 and B2F models must be connected to a 3340-A2 or A2F unit acting as head of string. Internally, the IBM 3344 aligns closely with the IBM 3350; differences are confined to variations in control unit microcode.

IBM 3350

Launched in 1975 for IBM System/370, the IBM 3350 Direct Access Storage Facility carried the code name Madrid. It introduced sealed, non-removable head-disk assemblies (HDAs) that combined heads and arms into a single sealed unit—a design that set a new standard for IBM DASD going forward. Each HDA contained 555 cylinders, equipped with 30 heads, and featured tracks holding approximately 19,069 bytes each, culminating in roughly 317 MB per assembly.

Models such as A2, A2F, B2, B2F, C2, and C2F comprised two HDAs per unit. The A2 and A2F models included an extra electronic board facilitating connection to the control unit—often referred to as controllers or head-of-string units. These devices were arranged in strings beginning with an A2 or A2F unit followed by up to three B2 units or combinations including C2 units. Typically, the A2 unit possessed a string switch enabling linkage to two storage control units (for example, a Model 3830 or Integrated Storage Controller within CPUs like the IBM 3148). Later controller models such as the IBM 3880 maintained backward compatibility with these configurations. The C2 unit also contained a controller that provided an alternate path if the controller in the A unit failed but offered limited connectivity options.

Permissible string configurations for IBM 3350 devices included -A, -AB, -ABB, -ABBB, -AC-, -ABC-, and -ABBC- arrangements.

Models designated with "x2F" suffixes (e.g., A2F) featured fixed-head areas covering the first five cylinders on both HDAs, effectively eliminating seek time for those cylinders. This reserved region was generally used for frequently accessed checkpoint data such as HASP or JES2 files, enhancing spool device throughput by minimizing head movement delays. It also accommodated TSO swap data along with system swap data for OS/360 successors like MVT and SVS as well as MVS systems—improving efficiency when switching contexts between interactive users or batch jobs.

The production and support for the IBM 3350 family concluded in September 1994.

IBM 3370

Debuting in January 1979 for IBM 4331, 4341, and System/38 midrange systems, the IBM 3370 Direct Access Storage Device incorporated seven fixed 14-inch platters, delivering a storage capacity of 571 MB per unit. It was pioneering as the first hard disk drive to implement thin-film head technology, which originated at the Thomas J. Watson Research Center during the late 1960s. The 3370 utilized a fixed-block architecture and was compatible with DOS/VSE and VM operating systems on S/370 platforms.

IBM 3375

The IBM 3375 functioned as a complementary device employing count key data architecture, necessary for operating systems such as OS/360 and its successors.

IBM 3380

Introduced on June 11, 1980, the IBM 3380 Direct Access Storage Device featured thin-film head technology and offered a capacity of 2.52 GB per unit—comprising two hard disk assemblies, each with two actuators accessing 630 MB. It supported data transfer speeds up to 3 MB/s and delivered an average access time of 16 milliseconds. Initial pricing was set between $81,000 and $142,200. Due to tribological challenges affecting the interaction between heads and media, shipments commenced in October 1981.

The typical setup included one A unit accompanied by up to three B units; each 3380 contained four devices, enabling configurations with up to sixteen devices in a string. Generally connected to a 3880 storage control unit via two paths, the system allowed two concurrent I/O operations directed at different HDAs.

In February 1985, IBM released the Extended Capability Models (3380 E) featuring double density and a capacity of 5.04 GB per unit (two actuators at 1.26 GB each). Later, in August 1987, the triple-capacity model known as the 3380 K was announced, providing 7.562 GB per unit (two actuators at 1.89 GB each). The J and K models supported four-path operation with up to thirty-two devices per string when connected to a 3990 storage control unit, facilitating four simultaneous I/O processes.

The IBM 3380 family encompassed twelve distinct models: six A-units serving as string heads with added logic for storage control unit connectivity; five B-units designed to attach to A- or C-units; and one C-unit that interfaced directly with an IBM channel.

Manufacture of the IBM 3380 line continued until May 1996, representing an exceptional fifteen-year tenure in the market that surpassed typical disk drive product lifespans.

IBM 3390

Released in November 1989, the IBM 3390 Direct Access Storage Device series delivered capacities up to twenty-two gigabytes spread across multiple drives. System pricing varied from $90,000 to $795,000 depending on configuration and total storage.

A standard 3390 string consisted of a central A unit containing four or eight devices along with as many as two B units supporting up to twelve devices each. Operating in four-path mode through a connection to a 3990 storage control unit, it was possible to attach a second string of 3390 devices for a maximum of sixty-four drives.

Each Hard Disk Assembly (HDA) housed two actuator-head units along with platters; Model 1 HDAs offered unformatted capacities of 1.89 GB, while Model 2 doubled this to 3.78 GB per HDA. Announced in September 1991, Model 3 increased capacity by fifty percent to reach 5.67 GB per HDA; Model 9 followed in May 1993 with triple the original size at approximately 11.3 GB per HDA.

Unlike previous DASD units that relied on large AC motors coupled with belts, the IBM 3390 HDAs employed direct-drive DC motors enclosed within their assemblies. Notably, Model 9 represented IBM’s final Single Large Expensive Disk (SLED) design.

IBM 9345

Released in November 1990 as a Request for Price Quotation (RPQ) for IBM's SuperComputing Systems Extensions (SCSE), the IBM 9345 hard disk drive was developed at IBM's San Jose facility under the codename Sawmill. It offered a maximum capacity of 1.5 GB within a full-height 5¼-inch enclosure, utilizing eight 130 mm platters. Notably, it was the pioneer HDD to incorporate Magneto Resistive (MR) read/write heads.

IBM 9340

In October 1991, IBM launched the 9345 Direct Access Storage Device (DASD) as part of the 9340 channel-attached count key data (CKD) DASD family designed for IBM mainframes, including the ES/9000 series. The 9345 Model 1 contained two hard drives each with 1.0 GB capacity, while Model 2 featured two drives with 1.5 GB each.

From a functional standpoint, the 9340/9345 series closely resembled the 3990 and 3390 models but did not include the non-volatile RAM cache found in the 3990 and supported a shorter maximum block size compared to the 3390. The operating system’s Input/Output Supervisor (IOS) identified these devices through a specialized initializer named IECCINIT, which assigned device types reflecting their distinct attributes.

9330 family of disk drives

  1. The 9331 Diskette Unit models 1 and 11 housed a single 8-inch floppy disk drive; models 2 and 12 contained one 5-inch floppy disk drive.
  2. The 9332 Direct Access Storage Device incorporated the IBM 0667 hard disk drive.
  3. The 9333 High Performance Disk Drive Subsystem utilized either IBM 0664 or IBM 0681 hard drives depending on the specific model.
  4. The 9334 Disk Expansion Unit enabled connection of one to four SCSI hard disk drives to RS/6000 systems.
  5. The 9335 Direct Access Storage Subsystem featured the "Kestrel" hard drive developed at IBM Hursley in the UK—an 850 MB device with three large 14-inch platters and dual rotary actuators accessing multiple surfaces. This rack-mountable subsystem was introduced alongside the IBM 9370 Information System in October 1986. There are no documented OEM versions of this unit.
  6. The 9336 Disk Unit employed the IBM 0681 hard disk drive, also known as Redwing.
  7. The 9337 Disk Array Subsystem integrated IBM’s IBM 0662 (Spitfire) or IBM 0663 (Corsair) hard disk drives.

IBM 2310

The IBM 2310 Removable Cartridge Drive made its debut in 1964 with the IBM 1800 and subsequently in 1965 with the IBM 1130, likely commencing shipments with the latter in late ’65. It stored up to 512,000 sixteen-bit words (equivalent to 1,024,000 bytes) on an IBM 2315 cartridge. This cartridge consisted of a single oxide-coated aluminum platter encased within a plastic shell featuring openings for both the read/write arm and two heads.

IBM 5444

Introduced in September of 1969 as part of System/3 and developed at IBM’s Hursley laboratory in England under the codename Dolphin, the IBM 5444 utilized a disk cartridge containing one fourteen-inch platter. It was available in three configurations:

  • Model 1: included one fixed and one removable platter, each with one hundred tracks per surface; cartridge capacity totaled approximately 1.23 MB
  • Model 2: featured one fixed and one removable platter with two hundred tracks per surface; total capacity of about 2.46 MB
  • Model 3: contained only one removable platter with two hundred tracks per surface; capacity also around 2.46 MB

IBM 62GV

The IBM 62GV, which began shipping in May of 1974 from IBM’s Hursley lab in the UK under the codename Gulliver, initially offered a storage capacity of five megabytes. Subsequent versions (designated as Model 62TM) increased storage to ten megabytes and then further to fourteen megabytes. This model employed a Swinging Arm actuator paired with a single fourteen-inch platter. The Swinging Arm design, developed at Hursley, became IBM’s most widely licensed electro-mechanical innovation and has been adopted universally by hard disk drives since the early ’80s. Approximately 177,000 units of the IBM 62GV were sold, marking it as the first HDD to surpass sales of one hundred thousand units.

OEM and Small Systems Hard Drives

This segment details IBM hard disk drives provided as OEM components and designed for IBM small-scale systems such as the System/3, System/32, /34, /36, and AS/400. Drives are categorized by their OEM model numbers and organized according to their initial shipment dates.

IBM 0680

Introduced in 1979, the 0680 was utilized in IBM small systems and entry-level System/370 models as the 3310 direct access storage device. Officially announced as the 0680 OEM variant in September 1981, it was engineered at IBM’s Hursley laboratory in the UK under the project name Piccolo. This drive incorporated six 8-inch (210 mm) platters and initially offered a capacity up to 65MB, featuring an enhanced rotary actuator mechanism.

A double-capacity model, designated 62SW, was released in June 1984; however, its market penetration was limited due to its cost per megabyte being comparable to that of the 62GV.

IBM 0676

The 0676 made its debut in November 1982 as part of the 5247 Disk Storage Unit for the IBM System/23 Datamaster. Developed at IBM Rochester, Minnesota under the internal name 21ED, this 8-inch HDD initially provided storage options of either 15 or 30 MB through configurations of two or four disks. In 1983, it was incorporated into the S/36’s 5360 System Unit. By 1984, enhancements doubled its capacity by increasing the number of tracks per disk surface, leading to its deployment within the S/36’s 5362 System Unit.

IBM 0665

Launched in October 1985, the 0665 was integrated into the PC AT (5170) system unit. Created under the codename "Pixie" at IBM Rochester, this 5-inch hard drive offered capacities of 20, 30, and 44 MB.

IBM 0667

Beginning shipments in August 1986, the 0667 was developed at IBM Rochester with the codename "Grant." This full-height 5-inch ESDI HDD featured up to four 130 mm platters and a maximum capacity of 70 MB. It was available as an option on select PC RT models (6150, 6151, 6152) and within System/36 Model System Units (5363, 5364).

IBM 0669

Released in 1987 and developed at IBM Rochester under the project name "Grant-Prime," the 0669 was a full-height 5-inch HDD capable of storing up to 115 MB across four 130 mm disks. It functioned as the internal hard drive for both the System/36 5363 and Series 1 4956 System Units.

IBM 0671

Also introduced in 1987, the 0671 was crafted at IBM Rochester under the codename "Lee." This full-height ESDI hard drive supported up to eight 130 mm platters with a maximum capacity of approximately 316 MB. It marked IBM's first use of a thin metal film recording surface technology. In 1988, it was incorporated into the IBM AS/400 9404 System Unit configuration supporting two or three drives.

IBM 0661

The 0661 appeared in 1989 as model number 371. Developed jointly at IBM Rochester and Hursley under the codename "Lightning," this SCSI HDD featured up to eight disks measuring 95 mm each with fourteen heads providing a storage capacity of around 320 MB. A subsequent "Turbo" version offering a capacity increase to approximately 400 MB was introduced in 1990. This drive became standard equipment on multiple IBM platforms including the AS/400 System Unit Model CXX.

IBM 0681

Introduced in April 1990 from IBM Hursley with the codename Redwing, the 0681 represented the final hard disk drive developed at that site. It delivered capacities reaching up to approximately 857 MB within a full-height five-inch enclosure containing as many as twelve platters measuring 130 mm each. Notably, it was IBM’s first HDD to implement PRML (Partial Response Maximum Likelihood) data decoding technology. The drive formed part of the early-1992 launched 9333 Disk Drive Subsystem. By May of that year, an upgraded variant offering increased density with a capacity of about 1.07 GB was incorporated into this subsystem.

IBM 0663

Introduced towards the end of 1991 and internally known as "Corsair," the 0663 was a compact 3-inch hard disk drive featuring a half-height (1.6-inch) design. It provided a maximum storage capacity of 1 GB spread over eight 95 mm platters. This model was incorporated into specific PS/2 and RS/6000 systems and marked IBM's initial OEM HDD to utilize Magnetoresistive (MR) head technology.

IBM 0664

Released in November 1992, the 0664—codenamed "Allicat" at IBM's Rochester, Minnesota facility—was a full-height 5-inch hard drive with a height of 3.25 inches. It effectively merged two 3-inch drives to deliver up to 2.013 GB capacity across as many as eight 95 mm disks.

IBM 0662

The 0662, dispatched in June 1993 and known by the codename "Spitfire" from IBM Rochester, was a full-height (1-inch tall) 3-inch HDD offering 1.05 GB of storage distributed over three platters or five recording surfaces. It functioned as the internal storage component for both the 9336 Disk Unit and the 9337 Disk Array.

Floppy disk drive

IBM was a pioneer in floppy disk technology, launching the initial 8-inch floppy disk drive in 1971 primarily as a read-only medium for program loading. By 1973, IBM introduced its first read/write version with the release of the 3740 Data Entry System. Although IBM established foundational standards for the 8-inch floppy format, it did not commercialize these drives independently, allowing industry standards to develop externally.

At one point, IBM stood as the largest OEM purchaser of 5-inch floppy disk drives. Its preference for two-sided drives with a density of 48 tracks per inch played a significant role in setting this configuration as an industry benchmark. Despite having plans to manufacture these and smaller formats internally, IBM abandoned all such production efforts by 1985. Additionally, its attempt in 1983 to OEM the smaller 4-inch DemiDiskette did not succeed.

"Star" series of HDDs

On October 17, 1994, IBM Storage Systems unveiled three distinct hard drive families: the Travelstar series featuring 2-inch drives tailored for laptops, the Deskstar line utilizing 3-inch platters aimed at desktop computers, and the Ultrastar series with 3-inch drives designed for high-performance computing environments.

IBM's first HDD versus its last HDDs

The following table contrasts IBM's inaugural hard disk drive, the RAMAC 350, with its final trio of "Star" series OEM HDD models. This comparison underscores remarkable advancements in cost-efficiency and miniaturization alongside substantial improvements in storage capacity and operational performance.

Parameter (units) RAMAC 350 Ultrastar 146Z10 Deskstar 180GXP Travelstar 80GN Improvement over 46 years (max)
Announcement date Sep 1956 Jul 2002 Oct 2002 Nov 2002
Storage capacity (GB) 0.004 146 180 80 ~48,000×
Physical size (inches) 60×68×29 4×1×5.75 4×1×5.75 2.75×0.38×3.95
Physical size (mm) 1500×1700×700 102×25×146 102×25×146 70×9.5×100
Volume (in³) 118,320 23 23 4 ~29,161×
Volume (liters) 1,939 0.4 0.4 0.1
Weight (lbs) 2,140 1.7 1.4 0.2 ~1,244×
Weight (kg) 971 0.8 0.64 0.095
Power consumption (watts) ~2374 (8100 BTUs/hour), up to 5500 VA depending on model 16 10.3 1.85 ~1,283×
Power efficiency (MB/watt) 0.0016 9,125 17,476 43,243 ~27 million ×
List price (Template:US$) $34,500 ($234,000 adjusted to 2002 dollars) $1,200 $360 $420
Cost per megabyte (Template:US$) $9,200 ($68,000 adjusted to 2002 dollars) $0.0082 $0.0020 $0.0053
Areal density (megabits/in²) 0.002 26,263 46,300 70,000
Areal density (kilobits/mm²) 0.003 40,708 71,765 108,500
Volume density (gigabytes/in³) 0.00000003 6 8 20
Volume density (megabytes/cm³) 0.000002 388 478 1,203
Average latency (ms) 25 3 4 7
Average seek time (ms) 600 5.9 10.2 12
Data transfer rate (MB/s) 0.001 103 29.4 43.75


DASD Devices Beyond HDDs and FDDs

Within certain IBM operating systems, both HDDs and FDDs are categorized as DASDs (direct access storage devices). Additional DASD types encompass the following technologies:

IBM 7320 Drum

The IBM 7320 represents a magnetic drum storage unit that debuted in 1962.

IBM 2301 Drum

Introduced in the late 1960s, the IBM 2301 is a magnetic drum-based storage device.

IBM 2303 Drum

The IBM 2303, launched in 1964, is another example of a magnetic drum storage apparatus.

IBM 2321 Data Cell

Announced in 1964, the IBM 2321 Data Cell employs short strips of magnetic tape for data retention. It accommodates ten removable cells, each with a 40 MB capacity, summing to an aggregate of 400 MB.

IBM 3850 Mass Storage System

The IBM 3850 Mass Storage System, introduced in 1974, functions as a tape cartridge library that stages data onto IBM 3330 or 3350 disk drives. This system presents virtualized 3330 drives to the host environment.

See also

External links

Retrieved from "https://www.alfawiki.org/index.php?title=IBM_1302&oldid=28532"