The Digibox's internal hardware specifications are not publicly disclosed, however some details are clearly visible on the system. All early boxes except the Pace Javelin feature dual SCART outputs, an RS232 serial port, a dual-output RF modulator with passthrough, and RCA socketed audio outputs, as well as a 33.6 modem and an LNB cable socket. A VideoGuard card slot, as well as a second smart-card reader are fitted to the front (these are for the Sky viewing card and other interactive cards). All share an identical user interface and EPG, with the exception of Sky+ HD boxes which have used the new Sky+ HD Guide since early 2009. The DRX595 dropped the RF modulator outputs. A PC type interface was fitted internally to some early standard boxes but was never utilised by Sky. The latest HD boxes only have a single SCART socket but have a RCA/phono socket for composite video output. All Sky+ and HD boxes have an optical sound output.