In Progress

The history of magnetic digital data storage is beautifully documented here by Computer History dot org. Magnetic technology has been the primary method for storing the data since the first recorded device being a wire recorder publicized by Oberlin Smith in the Sept 8, 1888 issue of Electrical World.. Prior to that data storage with punch cards dates back to the mid-1700s.

Hard Disk Drive

Here’s the in-depth Wikipedia article and there’s also an history of IMB Magnetic Drives article. Another good resource is computerhistory.org. Below is a table with high-level timeline:

The simple design of the IBM GV (Gulliver) drive, invented at IBM’s UK Hursley Labs, became IBM’s most licensed electro-mechanical invention of all time, the actuator and filtration system being adopted in the 1980s eventually for all HDDs, and still universal over 50 years and 10 billion arms later. In this particular product, the heads remained with the disk in a removable data module; a packaging concept that marked the divergence of OEM disk drive industry from following IBM.

IBM offered the 3340 in different sizes in 1973, once the entry-level size with the 3348 disk module and 2 spindles of 35 MB for $62,500 US and a station with 4 spindles of 70 MB. The first real encapsulated Winchester, in which the read heads and disk unit were no longer separated, was the IBM 3350 with a capacity of 317 MB, which came onto the market in 1975. All subsequent models up to the hard disks in PCs did not change the functional principle of the Winchester drives, as they were soon called.

Al Shugart in a 2000 interview stated “the low mass lightly loaded head or, as some people call it, the Winchester head” was one of the four most significant events in the history of mass storage.

In combination these technologies provided:

• lower head flying height thereby increasing capacity by enabling bits on a track to be closer together
• dramatically reduced head cost through simplified design and low cost manufacturing processes.
• higher yields and reliability by having the heads and disks permanently associated.

The original manual is available on archive.org.

Eighties and Nineties

Over time, as recording densities were greatly increased, further reductions in disk diameter to 3.5” and 2.5” were found to be optimum. Powerful rare-earth magnet materials became affordable during this period and were complementary to the swing arm actuator design to make possible the compact form factors of modern HDDs.

By 1986, 10 MB was the most commonly used hard disk size, and most new corporate computers had hard drives. Most in the industry expected that 20 MB would soon become the new standard size. By the late 1980s, their cost had been reduced to the point where they were standard on all but the cheapest computers.

Most HDDs in the early 1980s were sold to PC end users as an external, add-on subsystem. The subsystem was not sold under the drive manufacturer’s name but under the subsystem manufacturer’s name such as Corvus Systems and Tallgrass Technologies, or under the PC system manufacturer’s name such as the Apple ProFile.

The IBM PC XT in 1983 included an internal 10 MB HDD; by 1985 internal HDDs outsold external drives for personal computers. When IBM began selling the XT without a hard disk, hard disk manufacturers that had only sold to OEM customers began selling to resellers, which bundled XTs with the non-IBM hard disks. Hardcards became popular upgrades for existing computers.

Two Thousands

HDD improvements have been driven by increasing areal density, listed in the table above. Applications expanded through the 2000s, from the mainframe computers of the late 1950s to most mass storage applications including computers and consumer applications such as storage of entertainment content.

Moores law is the observation that the number of transistors in an integrated circuit (IC) doubles about every two years, with minimal increase in cost.

In 2019, Western Digital closed its last Malaysian HDD factory due to decreasing demand, to focus on SSD production. All three remaining HDD manufacturers have had decreasing demand for their HDDs since 2014.

Solid State Drive

A solid-state drive (SSD) is a type of solid-state storage device that uses integrated circuits to store data persistently. It is sometimes called semiconductor storage device, solid-state device, or solid-state disk. Etymologically, “solid-state drive” partly refers to existing data storage devices like tape drives and hard disk drives, which all used a mechanically driven storage medium.

An SSD stores data in semiconductor cells, with its properties varying according to the number of bits stored in each cell (between 1 and 4). Single-level cells (SLC) store one bit of data per cell and provide higher performance and endurance. In contrast, multi-level cells (MLC), triple-level cells (TLC), and quad-level cells (QLC) store more data per cell but have lower performance and endurance.

Most SSDs use non-volatile NAND flash memory for data storage, primarily due to its cost-effectiveness and ability to retain data without a constant power supply. NAND flash-based SSDs store data in semiconductor cells, with the specific architecture influencing performance, endurance, and cost. A NAND gate (NOT AND gate) is a logic gate whose output is false only if all its inputs are true; thus its output is complement to that of an AND gate.

Portable Storage Devices

The history of the floppy disc we are most familiar with is documented on Wikipedia and the timeline follows.

A notable figure is Alan Field Shugart (September 27, 1930 – December 12, 2006),an American engineer, entrepreneur and business executive whose career is said to have defined the modern computer disk drive industry.

Beyond floppy

Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as “180X” (180 times 150 KiB/s).

USB Drive Inventor Debates

There was contention over who invented the usb flash drive. Wikipedia includes details.