Dell OptiPlex E1 Troubleshooting Manual page 120

Abbreviation
or Acronym Description
UL Underwriters Laboratories
UMB upper memory block
UPS uninterruptible power supply
USB universal serial bus
USOC Universal Service Ordering Code
V volt(s)
VAC volt(s) alternating current
VDC volt(s) direct current
VDE Verband Deutscher
Elektrotechniker
VESA Video Electronics Standards
Association
VGA video graphics array
VLSI very-large-scale integration
VRAM video random-access memory
W watt(s)
WH watt-hour(s)
XMM extended memory manager
XMS eXtended Memory Specification
ZIF zero insertion force
4 Diagnostics and Troubleshooting Guide