I came up with this task while trying to import .brd files hosted by Analog Devices into my Altium Designer. I only got the .brd no other files from the project. But importing the layout at least gave me the footprints of the components which saves a lot of time. However, following the instructions by the Altium Designer documentation was not successful to me. The problem was that Altium Designer needs the extracta.exe from OrCAD/Allegro PCB editor.
As a workaround I downloaded a free trial version from OrCAD which is limited to 15 days. After the installation of the trial version make sure to add the path of extracta.exe ( C:\Cadence\SPB_17.2\tools\bin) to the environment variables of your windows system otherwise Altium can’t find the the extracta.exe.
I tried to use the import wizard for Allegro .brd files which comes with Altium Designer 18, but it failed despite the fact that I run an Intel I9 with 32Gb RAM…. But using the instructions form the Altium Designer documentation finally worked for me.
Copy the files Allegro2Altium.bat and AllegroExportViews.txt located in the Altium installation path (C:\Program Files\Altium\AD18\System) into the project folder containing the example.brd (Allegro binary format). Run the CMD command in the explorer of your project folder to open a terminal. Run the command Allegro2Altium.bat example.brd to start conversion from .brd format to .alg (ASCII format) Run the Altium Designer import wizard for Allegro and start importing the example.brd.alg file. This generated me a .PcbDoc file hopefully it also works for you 🙂