shanbaum
thank you
actually i didn't find and answer yet, so this helped.
for those who are interested in a quick decision here it is.
if you create a new project there is a block of code in project1.lpr
{$IFDEF UNIX}{$IFDEF UseCThreads}
cthreads,
{$ENDIF}{$ENDIF}
so one has only to wipe out {$IFDEF UseCThreads} or define {$DEFINE UseCThreads}. i decided to modify it the second way
{$DEFINE UseCThreads}
{$IFDEF UNIX}{$IFDEF UseCThreads}
cthreads,
{$ENDIF}{$ENDIF}