Re: Optically Isolated RS232
First of all I would not relay on supply from RTC and DTR pins...unless you know how to set them, they are useless for you.
So, built yourself +5V to -5V circuit and this should fix the supply problem...
If you still want to try to use power from RS-232 port connect the RS-232 in "null modem" configuration; this will leave you with RTS (7) connected to CTS (8), DTR (4) connected with DSR (6) and CD (1).
Connect diodes (cathode) to RTS-CTS, DSR-DTR-CD and TX and anodes to negative supply and increase C1 value to 10uF.
Now Hyperterminal should work for you...