Linux operating system16 channel Looping, BNC4 x Audio line in, 1 x Audio line outComposite output (702 x 576)16 x TTL alarm I/P, 16 TTL O/PUp to 100 ips @ 1 CIF SimplexMonitor out: Composite:1 BNC, SVHS:1 Y/H, VGA 1, Spot (composite):4 BNCRecord resolution: 1 CIF @ 336 x 272, 2 CIF @ 672 x 272Built in CD-RW250 Gig HDD standard + optional 2 extra HDDSecondry storage: Int CD-RW, USB HDD, USB CD-RW, USB memory stick, SCSI HDD (RAID)RS-232C, RS-485 Serial PortsLAN (10/100 Base Ethernet) Standard RS-232C for external modem1 x Remote controller-IR Port240 VAC operation