recording the output from a computer

I have a Z1U and need to record the output from a variety of computers as new footage. I'm trying to test this with my own notebook and can't seem to get a signal with either the Firewire or S-Video cables connected between the camera and computer. I'm in VCR mode, I'm pressing the record/start and pause buttons simultaneously as per the instructions on the HandsOn tutorial DVD I have, but I'm not getting any images or sounds in the viewfinder. Hitting pause to go into record doesn't result in anything either. Help would really be appreciated by anyone whpo's figured this out.