Memory Stick is a removable flash memory card format, launched by Sony in October 1998 , and is also used in general to describe the whole family of Memory Sticks. This family includes the Memory Stick PRO, a revision that allows greater maximum storage capacity and faster file transfer speeds; Memory Stick Duo, a small-form-factor version of the Memory Stick (including the PRO Duo); and the even smaller Memory Stick Micro (M2). In December 2006 Sony added the Memory Stick PRO-HG, a high speed variant of the PRO, to be used for high definition still and video cameras.

History

The original memory stick was available in sizes up to 128 MB, and a sub-version, Memory Stick Select allows two banks of 128 MB to be on the same card. An 8 GB card was unveiled at the 2006 Consumer Electronics Show in Las Vegas and according to Sony, the Memory Stick PRO has a maximum potential size of 32 GB.

While the Memory Stick has outlived most other flash memory formats, with a longevity comparable to CompactFlash and Secure Digital (SD), it has never enjoyed as widespread popularity as these competitors; the majority of portable devices that use it are Sony and Sony Ericsson devices. The significant third-party licensees that manufacture Memory Sticks are SanDisk and Lexar.

The term is not to be mixed up with the popular usage of "stick" to describe a SIMM or DIMM of dynamic RAM or a USB flash drive.

Applications

Typically, Memory Sticks are used as storage media for a portable device, in a form that can easily be removed for access by a personal computer. For example, Sony digital compact cameras use Memory Sticks for storing image files. With a Memory Stick-capable reader (typically a small box that connects via USB or some other serial connection), a user can copy the pictures taken with the Sony digital camera onto his or her computer. Sony uses and has used Memory Sticks in digital cameras, digital music players, PDAs, cellular phones, the PlayStation Portable (PSP), and in other devices, and the Sony VAIO line of personal computers has long included Memory Stick slots. The exception for now is the A100 DSLR camera which actually has a CompactFlash slot, although the new A700 DSLR camera is compatible with Compactflash and Memory Stick Pro Duo formats.

Formats and form factors

Lexar 256 MB Memory Stick Select with memory switch.

Memory Sticks include a wide range of actual formats, including three different form factors.

Original Memory Stick

The original Memory Sticks were approximately the size and thickness of a stick of chewing gum, and came in sizes from 4 MB up to and including 128MB. In response to the storage boundaries of the original Memory Sticks, Sony introduced the now-uncommon Memory Stick Select, which was similar in concept to the way in which 5.25" floppy disks used both sides of a disk. A Memory Stick Select was two (or rarely four) separate 128 MB partitions which the user could switch between using a (physical) switch on the card. This solution was rather unpopular, but did allow for users with older Memory Stick devices to use higher-capacity flash memory. A special Memory Stick can be used by Sony's AIBO robot pet, to enable the use of Aiboware - software intended for use on AIBOs. The Sticks include a copy protection mechanism used by the robot, allowing users to write programs. These are referred to as programmable or programming Memory Sticks and are coloured pink. Only 8 MB and 16 MB versions are available.

Memory Stick PRO

The Memory Stick PRO, introduced in 2003 as a joint effort between Sony and SanDisk , would be the longer-lasting solution to the space problem. Most devices that use the original Memory Stick form factor support both the original Memory Sticks and the PRO Sticks; some readers that were not compatible could be upgraded to Memory Stick PRO support via a Flash ROM update. Memory Stick PROs have a marginally higher transfer speed and a maximum theoretical capacity of 32 GB. High Speed Memory Stick PROs are available, and newer devices support this High Speed mode, allowing for faster file transfers. All Memory Stick PROs larger than 1 GB support this High Speed mode, and High Speed Memory Stick Pros are backwards-compatible with devices that do not support the High Speed mode. High capacity memory sticks such as the 4 GB versions are expensive compared to other types of flash memory such as SD cards and CompactFlash.

Memory Stick Duo and PRO Duo

Memory Stick Duo Adaptor and Memory Stick PRO Duo.

Certain standard Memory Stick Duo and all PRO sticks are MagicGate compatible.

The Memory Stick Duo is slightly smaller than the competing Secure Digital format and roughly two thirds the length of the standard form factor. It was developed in response to Sony's need for a smaller flash memory card for pocket-sized digital cameras and cell phones. Memory Stick Duos are available in all the same variants as their larger cousins: normal ones limited to 128 MB, higher capacity PRO Sticks (called Memory Stick PRO Duo in the Duo form factor), with and without High Speed mode, and with and without MagicGate support. There's also a simple adaptor (often sold along with the Memory Stick Duo) which allows a Duo to be used in any device that can accept its larger cousins.

The normal and PRO versions of Memory Stick Duo are also used with the PSP, which when inserted into the Memory Stick Slot show saved game data, music, pictures, videos and games.

Memory Stick Micro

Memory Stick Micro and adapter.

In a joint venture with SanDisk, Sony released a new Memory Stick format on February 6, 2006. The Memory Stick Micro (M2) measures 15 x 12.5 x 1.2 mm - roughly one-quarter the size of the Duo, around the size of a fingernail - with 128MB, 256 MB, 512 MB, 1 GB, 2 GB and 4 GB capacities, with a theoretical limit of 32 GB. SanDisk has recently launched an 8 GB M2 memory stick. Maximum transfer speed is 160 Mbit/s. It comes with an adapter, much like the Duo Sticks, to ensure compatibility with current PRO devices.

Memory Stick PRO-HG

On December 11, 2006, Sony, together with SanDisk, announced a new version of Memory Stick. The Memory Stick PRO-HG evolved out of the PRO.

Specifications

Transfer speeds

Standard:

Maximum write speed: 14.4 Mbit/s (1.8 MB/s)

Maximum read speed: 19.6 Mbit/s (2.5 MB/s)

Duo/PRO Duo:

Transfer: 159 Mbit/s (20 MB/s)

Minimum write speed: 15 Mbit/s

Maximum write speed: 80 Mbit/s (High Speed PRO Duo)

Micro (M2):

Transfer: 160 Mbit/s (20 MB/s)

Form factors

Standard and PRO: 50.0 mm (W) x 21.5 mm (H) x 2.8 mm (D)

Duo and PRO Duo: 31.0 mm (W) x 20.0 mm (H) x 1.6 mm (D)

Micro: 15.0 mm (H) x 12.5 mm (W) x 1.2 mm (D) (i.e., ~1/4 the size of Duo)