Glossary Current: U U UDC UDX — UDX is an acronym for up-/down-/crossconversion, denoting a device or software which performs those three functions. Also known as UDC. UEFI UMD Under-monitor display (UMD) — Traditionally, a small physical text display device mounted underneath a monitor which can display a short label Unified Extensible Firmware Interface (UEFI) — The UEFI https://wikipedia.org/wiki/UEFI is the modern low-level platform firmware of PCs. Upconversion — Converting a video from a smaller raster size to a larger raster size. ×