A friend has a security camera at his house, which is hooked up to an old-fashioned VCR, that uses 6-hour video tapes. The friend has expressed annoyance at having to change the tape every 6 hours, and wants to upgrade to a Digital Video Recorder, which can save some hundreds of hours before its hard
disk gets full. At which point the device would start overwriting the oldest-saved data, of course.
However, what of the fact that when the DVR approaches the age of that VCR, its hard drive will die? Then an all new DVR will need to be purchased. This seems wasteful to me.
What my friend really needs is a Video Data Conversion Box, that can receive various video inputs, and then convert the data to a form suitable for saving on an EXTERNAL hard disk, via an appropriate cable --fiber optics, anyone? The connection standards to hard drives never seem to hold still! IDE, SCSI, Serial ATA, FireWire, USB, ... --all of which have a range of different flavors/speeds! --it looks to me that some stability in the connection standard might be achieved when they switch to fiber optics.
Anyway, when the disk drive dies, or you simply want a bigger capacity, you just replace it only, not the whole DVR system.