History and Evolution of Memory Cards

What is Flash Memory? What is it used for?

Flash memory is a compact and widely used electronic storage medium that can be electrically erased and reprogrammed. It can store data for long periods of time without being connected to a power source (unlike RAM, its memory is non-volatile). There are two types of flash memory that use the same basic technology but read and write data in slightly different ways - NAND and NOR flash memory.

Flash memory cards are commonly used in portable electronic devices such as digital cameras, mobile phones, laptops, computers, tablets, PDAs, portable media players, video game consoles, etc. Basically, it's hard to go a day without using at least one device that uses a flash memory card.

But how did it all start?

Although the concept of flash memory was around as early as the early 1980s, the first commercial memory card format - the PC Card - didn't appear until 1990.

(1) History and evolution of flash memory cards

1980s: Toshiba developed NOR flash memory from EEPROM (Electrically Erasable Programmable Read-Only Memory) in the early 1980s and launched it to the market in 1984. In 1991, the first NAND flash memory technology was also launched by Toshiba. NAND flash memory is a new (improved) configuration that reduces the storage unit area, thereby achieving a lower bit cost. Both flash memories were invented by Dr. Fujio Masuoka while working for Toshiba in the 1980s.

1990: PC Card (PCMCIA) is the first commercial memory card format. PC Card is a storage device designed for memory expansion of personal computers (notebooks or laptops) and was developed by the Personal Computer Memory Card International Association (PCMCIA), hence the name. It comes in three types, with different thicknesses, and is available in 16-bit or 32-bit versions. This breakthrough led to the creation of many devices based on the configurability of PC Cards, including network cards, modems, and hard disks. PC Cards are now used primarily in industrial applications and to connect devices such as modems. Since 1994, a number of memory card formats smaller than PC Cards have emerged, the first of which was the CompactFlash card.

1994: Compact Flash I (CF-I) and II (CF-II) are flash mass storage devices used primarily in portable electronic devices. The format and devices were originally specified and manufactured by SanDisk in 1994 in two different thickness versions. CF is physically larger than other flash cards and initially used NOR-type flash memory, which allows programs to be executed directly from flash memory without being copied to the device's random access memory (RAM). CompactFlash remains popular and is supported by many professional devices and high-end consumer devices such as Canon and Nikon digital cameras. CF cards are available in capacities up to 512 GB.

1995: SmartMedia Card (SM/SMC) is a NAND-based flash memory card standard introduced by Toshiba in 1995 as a successor to the computer floppy disk. SmartMedia memory cards ranged in capacity from 2 MB to 128 MB, which doesn't seem like much in today's photo. SmartMedia cards consisted of a single NAND chip embedded in a thin plastic card, and were among the smallest and thinnest of early memory cards (just 0.76 mm thick), making them susceptible to damage from bending. They were often used as storage for portable devices and were especially popular in digital cameras. In 2001, they accounted for nearly half of the digital camera market. As camera resolution increased, the format began to have problems. There were no cards larger than 128 MB at the time, and compact digital cameras had reached sizes where even SmartMedia cards were too large and inconvenient. Eventually, Toshiba switched to the smaller, higher-capacity Secure Digital (SD) card in 1999. SmartMedia memory cards are no longer manufactured.

1997: SanDisk and Siemens AG introduced the MultiMediaCard (MMC) in 1997. MMCs were available in capacities up to 512 GB and were used in consumer electronics. Since the introduction of the SD card (1999), MMCs have gradually lost popularity, but embedded MMCs (eMMCs) are still widely used as internal storage for portable devices, residing in Android or Windows Phones and even low-cost PCs, replacing more expensive traditional SSDs.

1998: The Memory Stick (MS) is a removable flash memory card format introduced by Sony in late 1998. Its capacity ranged from 4 MB to 128 MB. Later, many versions with larger maximum storage capacity, faster transfer speeds, and smaller size were introduced to the market. In the 2000s, Sony used the Memory Stick exclusively in its products such as the Cyber​​-shot digital cameras, WEGA, VAIO computers, and the PlayStation Portable handheld game console. But as SD cards became more popular, Sony also started supporting the SD card format in 2010. Today, Sony digital cameras use SD and SDHC memory cards, and no new cards have been released since 2010, and the Sony Memory Stick will most likely be discontinued.

1999: Secure Digital (SD) is a memory card format developed by the SD Card Association (SDA) for portable devices. The card was jointly launched in 1999 by SanDisk, Panasonic (Panasonic), and Toshiba as an improvement on the MultiMediaCard (MMC) and has become an industry standard since then.

2000: USB (Universal Serial Bus) was released and sold on the commercial market by IBM and Trek Technology. A USB drive is a plug-and-play data storage device, including flash memory with an integrated USB interface. USB sticks are commonly used for storage, data backup, and file transfer, and come in a variety of different sizes. They are supported by modern operating systems such as Windows, Linux, macOS, and other Unix-like systems, as well as many BIOS-based systems.

2003: The miniSD card was introduced in 2003 as a smaller version of the SD card. While the new cards were designed for mobile phones, they were often packaged with a miniSD adapter to be compatible with standard SD memory card slots. Micro SD cards were introduced in 2005 with capacities of 32, 64, and 128 MB, followed in 2006 by the micro M2 card (from 64 MB to 16 GB) and micro SDHC card (2 GB to 32 GB). Cards have continued to evolve in both capacity and speed.

2010: The SDXC memory card (Secure Digital Extended Capacity) was introduced in 2010, with the same size as its predecessor, but with storage starting at 64 GB and going up to 2 TB, while also being dust and water resistant, able to withstand up to 16 kg of pressure, and super fast. The card uses Microsoft's exFAT file system to handle large amounts of data and files. A micro SDXC version is also available. At this point, it's all about speed, size, reliability, storage space, and ruggedness.

2016: Samsung's Universal Flash Storage (UFS) is flash storage for digital cameras, mobile phones, and consumer electronics devices. It is designed to bring higher data transfer speeds and greater reliability to flash storage. UFS technology allows data to be written and read to the memory at the same time, and is expected to replace eMMC and SD cards (which can only perform one operation at a time). Samsung has already used UFS in some of its phones. They have launched UFS memory cards with 32, 64, 128, and 256 GB of space. However, while the speed and battery utilization of UFS cards are much better, SD cards are still more popular and preferred by vendors.

2018: The SDUC released in June 2018 follows in the footsteps of the original SD, SDHC, and SDXC cards, increasing the maximum storage capacity level again (from 2 TB to 128 TB) and speed again (1.58 times the previous version, to be exact). But it is not clear when these cards will be launched in the market.