I don't have an answer, but several ideas:

- try find a solution in the flashmagic forum (I admit I've not been there for ages but hope it is still there)

- instead of the target hardware, connect the "other end" of the cable to an another COM port, and run a terminal program there, to see whether FM is able to reach the serial port from within the "third party software" (you should see a stream of "UUUUU"...)

- if you are ready to go for the low-level solution, then read http://www.8052.com/users/wek...rvival.txt (plus the ISP description in the 'V51RD3 manual)

JW