Brian S wrote: >> I need my current FB4 app which does send and receive AppleEvents, to send a CFStringRef to a new FB5 app and then it sends back a reply message to my POS software. > The supporting code for sending an Apple Event ( i.e. SendAppleEvent ) uses pascal strings. SendAppleEvent sends any number of bytes. Only the target process name must be a Pascal string. > You won’t be able to use this FB statement with a CFString True, if you send a CFStringRef to another process, it cannot make sense of it because the address spaces are not shared. You have to obtain the CFString's data bytes and send them. // find the size dim as CFIndex dataSize fn CFStringGetBytes( cfString, fn CFRangeMake( 0, fn CFStringGetLength( cfString ) ), _kCFStringEncodingUTF8, 0, _false, 0, 0, @dataSize ) // allocate buffer dim as pointer dataPtr dataPtr = fn malloc( dataSize ) // read bytes into buffer fn CFStringGetBytes( cfString, fn CFRangeMake( 0, fn CFStringGetLength( cfString ) ), _kCFStringEncodingUTF8, 0, _false, #dataPtr, dataSize, 0 ) // send AE SendAppleEvent _"XXXX", _"YYYY", dataPtr, dataSize, "ToWhomItMayConcern" // clean up free( dataPtr ) Robert P.