Just try to compile the units with FPC.
E. g. in a shell run
Code:
fpc -Pi386 -FuPath/To/Other/Units yourunit.pas
When you try this on Windows you should use "\" of course. If you need to compile for Win64 then you need to use this instead of "-Pi386":
If you get errors you might need to add the following between "
unit bla;" and "interface":
Delphi-Quellcode:
{$ifdef fpc}
{$mode delphi}{$H+}
{$endif}
Also you might need to correct some types. If you have types that are different from Delphi to Free Pascal then use the following construct:
{$ifdef fpc}TMyFPCType{$else}TMyDelphiType{$endif}
You can also use this inside the declaration of a function.
If you have errors you can't solve by yourself, then you might start a new topic in the FPC subforum.
Regards,
Sven