What is the DCD file format?
.dcd files are native drawing files created by DesignCAD, a 2D/3D CAD application developed by IMSI/Design, LLC. The format stores complete vector drawings in a proprietary binary container, including geometric entities, layers, dimensions, text annotations, and object metadata for both two-dimensional and three-dimensional designs.
DesignCAD originated in the early 1990s as one of the more accessible desktop CAD packages for Windows. The .dcd extension serves as the general-purpose drawing container; later versions of the software introduced the more specific .dc2 (2D drawings) and .dc3 (3D drawings) extensions to make the dimensionality of a file explicit at a glance.
Because the format is closed and proprietary, .dcd files carry no publicly documented magic bytes and can only be reliably identified by their file extension. For interoperability with other CAD tools, DesignCAD supports import and export of industry-standard formats such as DWG and DXF, as well as WMF, HPGL, and PDF output.
The current desktop application, DesignCAD 3D Max, continues to open legacy .dcd files. TurboCAD (also published by IMSI/Design) shares close lineage with DesignCAD and can handle the format as well. File sizes range from a few kilobytes for simple sketches to tens of megabytes for complex assemblies.
Security & safety
RISK: LOWCAD drawing files carry no active code. No known exploits for DCD format.
Format details
in a nutshell- CHARMM/NAMD Molecular Dynamics Trajectory - Binary FORTRAN single-precision file storing atomic coordinates over time, used by computational chemistry programs CHARMM, NAMD, GROMACS, OpenMM, VMD; endianness auto-detected.
- XML Document Content Description - A constraint description file (Document Content Description) for specifying structure rules for XML documents.
Programs that open DCD files
Windows2 apps
macOS1 app
Technical details
deep spec| Format type | Proprietary binary CAD drawing |
| Developer | IMSI/Design, LLC |
| Byte order | Little-endian |
| Geometry support | 2D and 3D vector entities (points, lines, arcs, surfaces, solids) |
| Layers | Named layers for organizing drawing elements |
| Text and dimensions | Text annotations and dimensional callouts stored natively |
| Magic bytes | None documented; identified by file extension only |
| Typical file size | 10 KB - 50 MB depending on drawing complexity |
| Platform | Windows; legacy Mac OS support |
| Interchange formats | DWG, DXF, WMF, HPGL, PDF (import/export) |
| Successor formats | .dc2 (2D drawings), .dc3 (3D drawings) |
| Released | early 1990s (DesignCAD for DOS/Windows) |
DCD conversions
Community Q&A
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