Changelogs and some history is provided in
Typically, over time a file format changes due to new features introduced and old ones or mistakes being removed. This section should provide some insight what changes were introduced in which version.
- OrCAD 9.2.3
- OrCAD 10.0
- OrCAD 10.3
- Initial (see here)
- OrCAD 10.5
- OrCAD 15.7
- Initial (see here)
- OrCAD 16.2
- OrCAD 16.5
- OrCAD 16.6
- Initial (see here)
- NetGroup enhancements (see here)
- Shapes for hierarchic blocks (see here)
- Introduced flag to indicate user specified references (see here)
- Introduce XML import/export and XSD schema (see here)
- Introduce user specific DRCs (see here)
- Introduce flag for waived DRCs (see here)
- Database upgrade (see here)
- QIR #1
- QIR #2
- QIR #3
- QIR #4
- QIR #5 (see here)
- QIR #6
- HotFix 32 QIR #7 (see here or here)
- HotFix 38 QIR #8 (see here)
- HotFix 51 (see here)
- Initial (see here)
- OrCAD 17.0
- OrCAD 17.2
- OrCAD 17.4
- OrCAD 22.1
- Initial (see here)
What exactly is this format? OrCAD can export libraries (and probably schematics) to an SDT file format that was already reverse engineered.
https://pcengines.ch/orcad.htm
https://pcengines.ch/orcadff.htm
The format seems really old, but maybe the current file format is somehow based on the old one?