I just bought a used PowerMac G3 (Yosimite). I've got a whole bunch of data on an external HD that I use with my PC. I thought I could just plug it into the USB port of the MAC and copy the data to the MAC but, as discussed earlier in this thread, this does not work. This is a real disappointment since I thought MACs were supposed to be so great (and I'm still hoping I find that they are). Obviously I cannot format the HD since that would erase all the data. I guess I could try what one participant suggested and that is, start with a new external HD and format it in such a way that it can be read by both the MAC and the PC. The whole point of buying the G3 was to learn about MACs and to be able to organize all the data I've accumulated on the PC. So, I need a way to transfer data back and forth. In another forum (on the transfer of data back and forth between PC and MAC) they suggested using a networking function and connecting the computers with a cable. However, this is not a good solution for me since the computers are located in different areas of the house. That's why I'm still hoping to be able to use an external HD to move data back and forth betweent the PC and the MAC. Any suggestions would be appreciated. I'm completely new to the MAC world.