causing the bits to “retain” the pattern as it is “burned in.” Firmware is nonvolatile. It will not be “forgotten” when the power is shut off. Handheld calculators contain firmware with the instructions for doing their various mathematical operations. Firmware programs can be altered. An EPROM is typically erased by using intense ultraviolet light.
Grayscale. Not a level of resolution, but a method of scanning and transmitting halftone images. Fax machines with grayscale abilities interpret photographs in levels of gray between white and black. The transmitting fax machine must have grayscale ability to send a photographic image accurately, but the receiving machine does not need it to print the image.
Group 3. Refers to fax machines that use digital encoding. These units transmit one page in less than one minute and produce resolution of 203 x 98, 203 x 196, or 203 x 392 lpi.
Group Dial. Sending one fax to multiple locations. Document is scanned once, then transmitted to multiple locations using a combined list (group) of programmed numbers. Different
from relay broadcasting, where one fax is sent to a remote machine. The remote machine then relays the fax to a group of fax numbers.
Halftone. See Grayscale.
Handshaking. A data interchange between telecommunications and/or computer equipment that “introduces” two systems to each other. For example, faxes use a handshaking protocol to identify the
Hub. See Relay broadcasting.
Hz (or Hertz). A measure of frequency equal to one cycle per second. Used in the specifications for a fax machine, it identifies the AC power the unit requires.
