H

.H:The extension for an include (or header) file in C.

HELPFILES:The environment variable used by a program to find .HLP files.

hexadecimal:The base-16 numbering system whose digits are 0 through F. The letters A through F represent the decimal numbers 10 through 15. Hexadecimal is easily converted to and from binary, the base-2 numbering system the computer itself uses.

highlight:To select an area in a text box, window, or menu as a command or as text to be deleted or copied. A highlight is shown in reverse-video or a bright color.

high memory:Memory between the 640K of conventional memory and the 1MB limit of a PC's address space.

HIMEM.SYS:An example of an XMS server. HIMEM.SYS manages extended memory for an 80286 or higher processor.

.HLP:The extension for a help file created by HELPMAKE.

HPFS (high-performance file system):An installable file system that uses disk caching and that allows filenames to be longer and to contain certain nonalphanumeric characters.

huge memory model:A program with multiple code and data segments, and data items that can exceed 64K.