OK, for drivers for your RS232 device, see wacio's post above your's - he has kindly provided a link to suitable drivers for the Nokia CA-42 cable. I wonder if wacio can help with GND connections. I have no experience of using this Nokia cable so now I'm only guessing: but the GND connections must go somewhere, at the very least to the GND connection on the HDD. The loopback test (where Rx & Tx wires are connected) will work REGARDLESS of whether there is a good GND connection to any subsequent hardware (such as your HDD in this case), so in some respects is quite a poor OVERALL test of connectivity to the HDD. In other words the loopback test tests ONLY the funtionality of the connection from HyperTerminal to the TTL output levels of the RS232 level shifting hardware and back again. Cheers, Andy PS reason for so much confusion is that there are many different ways being suggested (all of which do work) of connecting an RS232 level shifter to the HDD and power supply configurations - what I see therefore is some tips for one suggested kind of connection being incorrectly applied or assumed for another type of connection. The biggest confusion is that of power supplies and GND referencing of all the hardware. To me there are 3 kinds of connection being recommended: 1) Using COM port 1 and a mobile phone 'cable' (such as the Nokia CA-42) - these cables use a built in RS232 level shifter. 2) Using COM port 1 and a homebrew RS232 level shifter based on a chip (IC) such as the MAX232 or MAX3232. 3) Using an RS232 to USB converter 'cable' from eBay. Notes: o) Regardless of the cable being used, Power the HDD using a spare 15-pin SATA power cable from the PC that you intend to run HyperTerminal on. o) There is no actual power supply avaiable from the 9-pin DIN sockets found on PC serial COM ports *. Therefore any RS232 level shifting hardware (options 1 & 2 above) must be powered somehow and this power referenced to GND - hence the suggestion of using 3V button cells to do this. o) Unlike the serial COM ports, USB ports DO provide power, hence no need to provide an extra power source for these types of cables. o) For all 3 types of connection, the loopback test will ONLY test the RS232 level shifting hardware and HyperTerminal communication (turn echo off to test). It does not test that same connection to the HDD, i.e. correct GND connection, Rx and Tx connectivity. Based on this, I'd say the easiest cables to use would be those that are plugged into the USB port - these cables do however need software drivers to be installed such that the USB connection appears as a COM port for use in HyperTerminal. * Some of you may argue that there is a power source available from the COM port - this is not entirely true but these COM ports can be 'tricked' into providing one - hence the source of more confusion. A weak supply can be taken from the RTS & DTS pins of the COM port SO LONG AS THE SOFTWARE THAT DRIVES THE PORT IS CONFIGURED TO DO SO.