Cadence offers official time-limited trials (typically 30 days) of current versions. This is legal, safe, and fully functional.

For maintaining legacy 16.6 projects, contact Cadence support or an authorized reseller. Sometimes they can provide access to old versions for existing license holders.

Cadence provides a free, feature-limited version of OrCAD Capture and PSpice for non-commercial use. Limitations include:

If you truly need version 16.6 specifically:

OrCAD 16.6 is a legacy PCB design suite from 2013–2014, part of Cadence’s product line. It includes:

Operating system: Windows 7, 8, 8.1, 10 (32/64-bit)

Hotfixes: The final update for 16.6 was Hotfix 124 (around 2017). Pirated torrents rarely include current hotfixes.

Consider these free EDA tools instead of pirating: