History of hard disk drives facts for kids

Hard disk drives, often called HDDs, are like the long-term memory of a computer. They store huge amounts of digital information, from your favorite games and photos to important documents and the computer's operating system. Unlike a computer's main memory (RAM), hard drives keep data even when the power is turned off.

The idea for a "Random Access File" that could store a lot of data and find it quickly was first thought up by IBM in 1953. Engineers at IBM's lab in San Jose, California, invented the hard disk drive. This invention created a new way for computers to store information, which we now call secondary storage. It was cheaper and slower than the computer's main memory at the time, but much faster and more useful than older methods like tape drives.

Commercial use of hard disk drives began in 1957 with the IBM 305 RAMAC system, which included the IBM Model 350 disk storage. This invention was so important that a patent for disk drives was granted in 1970.

Over time, hard drives became smaller, more reliable, and easier to use. The very first drives were huge and only worked in special, protected rooms called data centers. But as technology improved, they started appearing in factories, offices, and eventually, in almost every home computer.

Hard Drives: Growing Bigger, Getting Smaller

The first hard drives used large disks that were 24 inches across! Imagine a disk as big as a pizza tray inside your computer. Over the years, these disks shrank a lot. Today, the most common sizes are 3.5 inches for desktop computers and 2.5 inches for laptops. The really big, old drives often needed their own large cabinets and a lot of electricity. Smaller drives fit neatly inside standard computer cases.

Capacity: From Megabytes to Terabytes

The amount of data hard drives can store has grown incredibly fast. When hard drives first became available for personal computers, they could only hold about 5 megabytes of data. To give you an idea, that's less than a single high-quality photo today!

By the mid-1990s, a typical hard drive for a PC could store about 1 gigabyte. Today, desktop hard drives can hold anywhere from 1 to 8 terabytes, and some of the biggest ones can store up to 20 terabytes! Laptop drives are smaller but still hold a lot, up to 5 terabytes.

The number of hard drives made each year reached its highest point in 2010, with about 650 million units shipped. Since then, the number has slowly gone down as other storage options, like SSDs, have become more popular.

The Early Days: 1950s-1970s

The very first hard drive, the IBM 350 Disk File, was developed by an IBM team led by Reynold B. Johnson. It was announced in 1956 with the new IBM 305 RAMAC computer.

The IBM 350 RAMAC: A Giant Leap

The IBM 350 drive was massive, with fifty 24-inch disks. It could store five million 6-bit characters, which is about 3.75 megabytes. A single part with two "heads" moved to read and write data on all the disks. It took almost a second to find information, which was very fast for its time!

This RAMAC disk drive created a new level of computer storage. It was slower and cheaper than the computer's main memory (which was often core or drum memory), but much faster and more expensive than tape drives. For about 20 years, other technologies tried to compete with disks, but hard drives eventually won out. Today, SSDs are the main competitors to HDDs.

Flying Heads and Removable Disks

In 1961, the IBM 1301 Disk Storage Unit introduced a big improvement: "self-flying heads." These heads floated on a cushion of air very close to the disk surface, which made them much more reliable.

The first hard drive to use removable storage was the IBM 1311 drive, introduced in 1962. It used "disk packs" that you could take out and swap, each holding two million characters. Later versions, like the IBM 2314, could store 29 megabytes per pack.

The "Winchester" Drive

A very important step forward happened in 1973 when IBM introduced the IBM 3340 "Winchester" disk drive. This was the first time hard drives used special, low-weight heads that touched the lubricated disk surface only when the drive was off. The name "Winchester" came from the plan to have two 30-megabyte sections, like a "30-30 Winchester rifle." This technology became the standard for hard drives for many years.

Also in 1974, IBM invented the "swinging arm" actuator. This simple design, which moves the read/write heads across the disk, became incredibly popular and is still used in hard drives today.

By the end of the 1970s, smaller 8-inch and 5.25-inch disks started to become common.

1980s: The Rise of Personal Computers

The 1980s were a time when personal computers (PCs) started to become popular. While large 14-inch hard drives were still used for big computer systems, smaller "Winchester" drives were clearly the future.

Hard Drives for Everyone

At first, hard drives were very expensive and rare for PCs. Most early personal computers used slower floppy disk drives or even cassette tape drives to store information. But by the late 1980s, hard drives were a standard part of almost every PC. Floppy disks were then mostly used just to move files between computers.

The IBM PC XT in 1983 was one of the first popular PCs to include a standard 10-megabyte hard drive. Soon, internal hard drives became common in personal computers.

Hard drives continued to shrink. The 3.5-inch size was introduced in 1983, and the even smaller 2.5-inch size appeared in 1988.

By 1989, about 22 million hard drives were being sold each year, showing how quickly they were becoming essential.

1990s: Consolidation and Growth

Even though many new companies tried to make hard drives in the 1990s, the number of manufacturers actually decreased. The industry started to focus on the 3.5-inch and 2.5-inch sizes, while larger and some smaller experimental sizes faded away.

During the 1990s, the number of hard drives sold and the money earned by the industry steadily increased. By 1999, 174 million units were shipped.

2001 to Present: New Challenges and Innovations

In 2001, the hard drive industry saw its first ever drop in sales. Over the next few years, the number of companies making hard drives shrank even more. By 2013, only three major manufacturers remained: Seagate, Toshiba, and Western Digital.

Key Events and Innovations

• 2009: Fujitsu sold its hard drive business to Toshiba.
• 2011: Major floods in Thailand hit many hard drive factories, causing a worldwide shortage and doubling prices for a while.
• 2012: Western Digital released very thin 2.5-inch drives for laptops.
• 2013: HGST (now part of Western Digital) shipped the first modern hard drive filled with helium gas. Helium helps the disks spin more smoothly and allows for more platters inside, increasing capacity.
• 2013: Seagate claimed to ship the first drives using a new technology called shingled magnetic recording (SMR), which packs data even more tightly.
• 2021: 20 TB drives using HAMR (Heat-Assisted Magnetic Recording) technology were released, pushing storage limits even further.

Unit production of hard drives peaked in 2010. Since then, the number of units shipped has slowly declined as SSDs have become more popular, especially for faster computers. However, hard drives still offer the most storage for the lowest cost, making them important for storing huge amounts of data.

Timeline of Hard Drive Milestones

• 1956: IBM 350A prototype, the very first disk drive.
• 1957: IBM 350, first production disk drive, storing 3.75 megabytes.
• 1961: IBM 1301 introduced "flying heads" that floated on air.
• 1962: IBM 1311 introduced removable disk packs.
• 1968: Memorex was the first company to ship a hard drive that could work with IBM systems, starting competition.
• 1973: IBM 3340 "Winchester" drive introduced sealed disk packs with heads inside.
• 1974: IBM 62GV "Gulliver" introduced the "swinging arm" actuator, a design still used today.
• 1979: IBM 0680 Piccolo, the first 8-inch hard drive.
• 1980: The IBM 3380 was the world's first gigabyte-capacity disk drive (1.26 GB), but it was huge and expensive!
• 1980: Seagate released the first 5.25-inch hard drive, the ST-506, with 5 megabytes of storage.
• 1983: The first 3.5-inch hard drive was released.
• 1988: PrairieTek 220, the first 2.5-inch hard drive.
• 1991: IBM 0663 "Corsair," the first hard drive using magnetoresistive heads, which allowed for much higher data density.
• 1992: Seagate shipped the first 7,200-rpm hard drive (Barracuda), spinning faster for quicker access.
• 1997: IBM Deskstar 16GB "Titan," the first drive with Giant Magnetoresistance heads, a major breakthrough for capacity.
• 1999: IBM released the Microdrive, a tiny 1-inch hard drive.
• 2002: Seagate shipped the first Serial ATA hard drives, a new, faster way to connect drives to computers.
• 2005: First hard drive using perpendicular magnetic recording (PMR) shipped, allowing data to be stored vertically, increasing density.
• 2010: First hard drive using Advanced Format (4,096-byte sectors) for more efficient storage.
• 2013: HGST shipped the first helium-filled hard drive.
• 2021: 20 TB HAMR drives were released.

Manufacturing History: Where Hard Drives Are Made

Hard drive manufacturing started in California's Silicon Valley in 1957 with IBM. The industry grew, with more companies joining in the 1960s and 1980s, reaching a peak of 75 manufacturers in 1984. However, over time, many companies either went out of business or were bought by larger ones. Today, only three main companies make hard drives: Seagate, Toshiba, and Western Digital.

In the early days, most hard drives were made in the United States. But in the 1980s, companies like Seagate started moving their production to Singapore and other parts of Southeast Asia. By 1990, Singapore was making 55% of the world's hard drives. Today, all three remaining companies produce their hard drives in the Pacific Rim region. While the manufacturing itself moved, many of the design and engineering teams for hard drives are still located in places like Silicon Valley.