Memory Stick

Memory Stick (sometimes abbreviated as MS) 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.

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 don't 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

The MagicGate standard for Memory Sticks is an encryption system allowing music to be downloaded to the card and played back by an authorized device, but not shared. Certain standard Memory Stick 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 adapter (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 and videos

Memory Stick Micro

In a joint venture with SanDisk, Sony released a new Memory Stick format on February 6, 2006. The Memory Stick Micro (M2) measures 15 × 12.5 × 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. 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.