An MS12 file is a CAD file created with version 12 of Multisim, a program used for printed circuit board (PCB) design, simulation, and analysis. It contains a circuit schematic designed by the user. MS12 files can be simulated in the software to analyze the circuit.

MS12 and MP12 files are the primary file types associated with Multisim. You can simply double-click the MS12 file to open it in Multisim. Also, MS12 files can be combined into Multisim projects, which use the .MP12 extension. Multisim appends a number to circuit design file extensions, which indicates the version of Multisim that created the design. For example, Multisim 10 uses the .MS10 file extension and Multisim 11 uses the .MS11 file extension for saving designs. Also, Multisim supports older project formats, which means that version 14 of Multisim can open an .MS11 design created by version 11 of Multisim. Multisim provides a variety of features that make it a powerful electronic schematic capture and SPICE environment. It is used by educators, researchers, and engineers around the world to simulate and analyze PCBs.