+ PS1: initialize the thread manager in the system unit

rtl/ps1/system.pp

@@ -145,4 +145,9 @@ begin
 
   { Reset IO Error }
   InOutRes:= 0;
+
+{$ifdef FPC_HAS_FEATURE_THREADING}
+  { Initialize the thread manager }
+  InitSystemThreads;
+{$endif}
 end.