hello everybody!

I have a 8051 board with emon51 monitor program. Using hyperterminal, comands like execute, modify data mem, regs are working.
However, on download command 'H' , 8051 returns with spade sign and stops response.
I have tried using V25com serial interface but this time 8051 board returns nothing.

I am sure that I have specified the correct port configured correctly
(baud rate 4800, 8-N-1).
I need to know how can I download hex files to 8051 board either using hyperterminal or V25com?

Can anybody help?
Thanks,
Arup