Contributor: WILLEM JOOSTEN { >> Does any body have source code to tell me if my program >> is being debugged with TURBO DEBUGGER. ? It is possible to detect if your program is debugged. Debuggers use interrupt 3 for breakpoints. The following example will simply crash the program if its run with Turbo Debugger, under DOS there's no problem. CAUTION : this program wil crash if run under a debugger, including the IDE (when you make use of breakpoints) } Program DebugTest ; Uses DOS ; var OldInt3 : Pointer ; {$F+} Procedure Int3 ; assembler ; ASM end ; Begin GetIntVec (3, OldInt3) ; SetIntVec (3, @int3) ; { Put breakpoint here } Writeln ('Breakpoint action ?') ; SetIntVec (3, OldInt3) ; end.