The first commercially available hard disk drive was the IBM 350 which was introduced in 1956. This groundbreaking device was the size of a large refrigerator and could hold a maximum of 3.75 megabytes (MB) of data. To put that capacity into perspective, a single modern MP3 song takes up 3-4 MB of storage space. So the pioneering IBM 350 could only hold around 1,000 songs total.
The Invention of Hard Disk Drives
Hard disk drives were invented in the 1950s as a way to store data magnetically on large rapidly rotating platters coated with material that could be magnetized and demagnetized repeatedly. This allowed for much greater data capacity than existing punchcard systems and magnetic tape drives which were sequential access only. Some key innovations that enabled hard drives included:
- Sealed environment – Hard drives have airtight cases to allow the platters to spin rapidly in a dust-free environment.
- Low friction spindle – The platters spin around a spindle which uses bearings to reduce friction.
- Read/write arm – An arm with a read/write head glides just above the disk surface to access data without touching the platter.
- High precision – All components are engineered with extreme precision to allow the head to read data from the quickly spinning disk.
With these innovations in place, hard disk drives could reach capacities of several megabytes on the same footprint that tape drives could only manage a few kilobytes. The potential was immediately clear for businesses that needed to store large amounts of data.
IBM 350 Disk File
In 1956, IBM announced what many consider the first hard drive – the IBM 350 Disk File. It boasted a total storage capacity of 3.75 MB on fifty 24-inch platters. To access data, the 350 used an actuator arm with read/write heads that moved up and down to different platters. This allowed random access to stored information as opposed to sequential access like tape drives.
Some key specs on the IBM 350 Disk File include:
- 50 x 24 inch platters providing 2,000 surfaces for data storage
- 200,000 bits per square inch of disk surface
- 7.5 million bits total capacity = 3.75 MB
- Two independent actuators with 10 read/write heads each
- 7200 RPM spindle speed
- Average seek time of 600 ms
- 600 lb total weight
- Required an air conditioning system due to heat generated
The 350 was about the size of two refrigerators and weighed over 1/4 ton. It had to be fork lifted into data centers. But for the first time, applications with very large datasets like payroll systems and inventory databases could be computerized. The 350 pioneered the use of heads moving rapidly across the radius of spinning platters to provide random access.
Market Adoption of Hard Drives
Despite the high cost, large size, and air conditioning needs, initial uptake of hard disk drives was strong among organizations that needed to store and access large amounts of digital data. A few examples include:
- Banking – Banks could store financial records and access accounts, balances, etc. randomly.
- Insurance – Policy details and claims databases could be stored and accessed.
- Government – Census and tax data could be stored in databases.
- Scientific – Data from weather modeling, nuclear tests, aerospace research etc. needed storage.
Hard drives allowed structured storage instead of just filing cabinets full of paper records. Arithmetic operations like interest calculations could be applied. Reporting and aggregation became possible.
During the 1960s and 1970s additional improvements were made including replacing vacuum tube electronics with printed circuit boards, integrating the controller into the hard drive unit, and developing the first hard drive for minicomputers – the IBM 2314 with a capacity of 29 MB.
By 1980, hard drive capacities reached the gigabyte range with the introduction of the IBM 3380 with 2.52 GB of storage. This pioneered the use of thin film heads and sealed disks. Density and capacity continued increasing rapidly from there.
Cost of Hard Drives Over Time
One of the major limitations on adoption of hard drives in the 1950s and 1960s was the very high cost compared to alternatives like punched cards and magnetic tape. In 1956, the IBM 350 hard drive itself cost $35,000 which would be over $350,000 in today’s dollars. Leasing the drive and an IBM mainframe computer brought the monthly cost to over $15,000 equivalent to $150,000 today.
Only major corporations, government agencies, and research institutions could afford that. But costs dropped dramatically in subsequent decades:
| Year | Model | Cost Per MB |
|---|---|---|
| 1956 | IBM 350 | $10,000 |
| 1980 | IBM 3380 | $200 – $500 |
| 2000 | Maxtor DiamondMax 80GB | $1 |
| 2020 | 2TB Hard Drive | $0.02 |
So in the span of just 45 years, costs declined by a factor of 500,000x from 1956 to 2000. This drove mass adoption of hard disk storage not just in business, but in consumer devices like PCs.
Businesses Benefit from New Database Capabilities
Hard disk drives revolutionized business data processing by enabling affordable random access to large datasets. Some examples of the transformative business applications enabled include:
- Inventory Control – Retailers could track products, volumes, locations in storage or on shelves etc. This data could be queried as needed rather than just in report printouts.
- Accounts Receivable/Payable – Invoices, purchase orders, etc. could be efficiently recorded and processed.
- Payroll – Employee payroll records could be maintained and rapidly updated each pay period.
- Sales Automation – Customer details, orders, and order status could be tracked.
- Airline Reservations – Airline schedules and seat availability data could be stored and reservations booked, changed, or cancelled online.
Having all of this data online and rapidly accessible transformed business operations. Executives and employees could get up to date reports on important metrics any time. Online transaction processing allowed many manual paper processes to be automated. The potential was now open for true enterprise resource planning systems.
Improvements in Hard Drive Capacity
The IBM 350’s capacity was quickly dwarfed as new disk drive innovations were introduced over subsequent years:
- CBI 4300 – In 1962 introduced the first hard drive using a single platter instead of dozens. This reduced latency and increased capacity to 10MB.
- IBM 1301 – The 1301 in 1961 introduced removable hard drive “disk packs” containing six 14-inch platters for 62.5 MB total capacity.
- CDC 844 – Control Data Corporation drives increased capacity to 500 MB by the late 1960s with faster 7200 RPM spin speeds.
- IBM 3340 Winchester – Sealed drives introduced in 1973 cut airborne contamination leading to 70MB capacity.
- IBM 3380 – Thin film heads contributed to drive densities of 887 MB by 1980.
Key Hard Drive Capacity Milestones
| Year | Model | Capacity | Details |
|---|---|---|---|
| 1956 | IBM 350 | 3.75 MB | 50 x 24 inch platters |
| 1962 | CBI 4300 | 10 MB | Single platter design |
| 1968 | CDC 844 | 500 MB | 7200 RPM spindle speed |
| 1973 | IBM 3340 | 70 MB | “Winchester” sealed drive |
| 1980 | IBM 3380 | 2.52 GB | Thin film heads |
| 1991 | IBM 0663 | 1 GB | First 1 GB drive |
So in around 35 years, hard drive capacities increased by a factor of over 250,000x from megabytes to gigabytes! This helped usher in the personal computer revolution in the 1980s as suddenly reasonably priced PCs could have 10s of megabytes for an operating system, programs, and files.
The PC Revolution
Prior to the late 1970s, computers were mainlyframe systems costing hundreds of thousands to millions of dollars. The idea of a “personal” computer for each individual was not practical due to limitations including storage. But the advent of smaller hard drives with capacities of 10s of megabytes made PCs viable. Key events include:
- 1970s – Early personal computers like the Altair used paper tape/cards for storage as floppy disks were initially too expensive.
- 1976 – The Apple I shipped without disk or monitor requiring users to supply their own. It had only 4 KB of memory.
- 1977 – The Apple II was one of the first mass market PCs. It supported external 5.25 inch floppy drives.
- 1981 – The IBM PC debuted with an internal 10MB hard drive option from Seagate for $1,500.
- 1982 – 10MB hard drives became standard on PCs allowing affordable computers for home and office use.
Within less than a decade, PCs went from niche hobbyist devices to a mainstream platform purchased by millions of businesses and consumers worldwide thanks to advancing capabilities like hard drive storage.
Hard Drive Growth by Decade
| Decade | Typical Desktop PC Hard Drive |
|---|---|
| 1980s | 10 MB |
| 1990s | 500 MB to 1 GB |
| 2000s | 80 GB to 160 GB |
| 2010s | 500 GB to 1 TB |
As PCs became more powerful and ran sophisticated applications like office suites, databases, media editing software, and games, demand for hard drive capacity skyrocketed. Capacities during the 1980s to 2000s regularly doubled year over year. Today, desktop PCs typically come with 500GB up to 1TB of capacity.
The Future of Hard Drive Storage
While new solid state storage technologies like SSD are now available and supplementing hard disk drives, HDDs continue advancing:
- Scaling Density – New techniques like shingled magnetic recording allow densities up to 2.5 TB per 3.5 inch disk today.
- Larger Capacities – 20TB+ drives are now available based on more platters and heads packed into the same chassis.
- Faster Speeds – SATA interfaces providing 6 Gb/sec and 12 Gb/sec throughput to SSD-like speeds.
- Cheaper Per GB – HDD costs per gigabyte remain well below SSD and continue dropping.
For mass storage of large data, video, backups, and more – hard disk drives still offer compelling advantages of capacity and affordability. Maximum capacities will continue growing, likely reaching 50+ TB within the next 5 years and 100 TB by 2030. While flash memory conquers the performance space, hard drives have staying power thanks to market needs for cost-effective high capacity bulk storage. The pioneers of the first hard disk drives in the 1950s would surely be amazed seeing storage measured in terabytes and costing just pennies per GB today.
Conclusion
The IBM 350 in 1956 was the first commercial hard disk drive and could hold just 3.75 MB of data total. Despite its limited capacity compared to today, it started a revolution by enabling affordable random access storage of business databases and records. Capacities rapidly rose from the megabyte era to gigabytes by the 1980s. This paved the way for the personal computing revolution with storage going from ~10 MB to 500 GB or more today. Hard drives continue evolving with larger capacities, denser recording, and faster speeds. While solid state drives are now preferred for performance, hard disk drives retain a solid position as a cost effective bulk storage solution into the future thanks to continually advancing capabilities.