Not so long ago the “State of the Art� CCTV system consisted of cameras a switcher of some sort and a VCR to record the information. If financing was not an issue, there could have been several VCRs dedicated to recording a single camera, set to sequence through the day. Standard VCRs with T-200 tapes could get approximately 8 hours of storage. Time lapse VCRs made recording less of a chore by expanding storage time to 24 hours or more. The next gizmo to come out was the multiplexer. This is a simple enough idea. The VCR and the multiplexer would be synchronized with each other. The multiplexer would send 1 image from each camera at a fraction of a second to the VCR. On playback, the multiplexer would then only show the images for the camera being requested. This setup worked satisfactory, but required frequent maintenance. The single channel DVR was intended to replace the VCR, it had higher quality, and storage capabilities, and other than failure, was maintenance free. Multi channel Dvr’s have the multiplexer capabilities incorporated into them. That leads us into today’s equipment, the modern day DVR.