4WD - you can try some tricks like putting an empty cassette in it (strip out the tape) and it thinks it is recording. My Sharp N1 from 1986 or so, would sit happily in preview mode continuously, but most don't. I just replaced the battery pack with the external power adaptor from the charger. It worked for about 3 years and it finally died 6 months after a cat peed on it...

It had better resolution than the personal webcams, I used a PCI AV/TV Capture card, a plug in USB device looks a whole lot better though! I now use an Olympus digicam for my main cam.
TK