DM2

DM2 is an format produced by version 2 Digital Micrograph, a program used in transmission electron microscopy. (Digital Micrograph version 2 is not to be confused with version 2 of Gatan Microscopy Suite ("GSM"), which Digital Micrograph was later subsumed into.) DM2 files contain data from the microscope, as well as a additional metadata, including a specification of how the image data should be displayed on a screen. It was succeeded DM3 at some point before 1999. There is no easily accessibly information about a "DM1" format, if it ever existed at all. It seems that Digital Micrograph version 2 was only for the (old) Macintosh platform.

Identification
DM2 files have a type code of "GSHN" and a creator code of "GCCD". Extrapolating from .dm3 and later, DM2 files would have the extension .dm2 if on a platform that uses extensions. This is directly claimed by dubious sources. . They will start with either or with, for Digital Micrograph versions 2.0 and 2.5, respectively; they will start with  regardless of version.

Links

 * Unofficial documentation
 * Official Digital Micrograph 2 website
 * Gatan Microscopy Suite