A Combo television unit, or a TV/VCR combo, sometimes known as a televideo, is a television with a VCR, DVD player, or sometimes both, built into a single unit. These converged devices have the advantages (compared to a separate TV and VCR) of saving space and increasing portability. Such units entered the market during the mid-to-late 1980s when VCRs had become ubiquitous household devices. By this time, the VHS format had become standard; thus the vast majority of TV/VCR combos are VHS-based. Most combo units have composite inputs on the front and/or back to connect a home video game console, a second VCR, a DVD player, or a camcorder. Some units may also include a headphone jack or S-Video inputs.Though nearly all TV/VCR combination sets have monaural (mono) sound though with stereo soundtrack compatibility, there are a large number of TV/VCR combos with a stereo TV tuner, but a mono VCR (some may even include a mono sound input alongside a composite video input. Some models from Panasonic also included an FM tuner.When DVDs were released, brands such as Toshiba introduced a TV/DVD/VCR combo. However, many of these units turned out to have unreliable DVD players and never had a large place in the TV market. Modern televisions tend to be mostly composed of solid state components, while VCRs require physical movement for both the inner workings of the VCR and the actual viewing of a VHS tape. VCRs also tend to require occasional service to upkeep the VCR, including things like cleaning the heads, capstan, and pinch rollers. For this reason, it is not uncommon for the included VCR to cease functioning or to become unreliable years before a similar fate befalls the television component due to lack of easy maintenance. As late as 2006, flat-panel TVs with integrated DVD players appeared on the market, and integrated TV/DVD sets started overtaking the TV/VCR market. This is due to both the low price and overwhelming availability of DVDs and more compact form factor, as opposed to the increasingly rare video cassettes and near-extinction of cathode ray tube displays in the consumer market.