Hi Paul,
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When I try to source synth.tcl , I receive error :
error: can't find package ::quartus:: project while executing "package require ::quartus:: project" (file "synth.tcl" line 34) invoked from within "source synth.tcl"
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Which Tcl console did you try to run the script from? It should be run from the Quartus Tcl console, not SystemConsole.
Note that the instructions indicate you should cd to the top-level of the project folder and issue "source scripts/synth.tcl", i.e., you should not have changed directory to the scripts folder and issued "source synth.tcl". The script uses the location you source it from to determine relative paths.
Cheers,
Dave