H

.H        	Header. File name extension.
HACMP           High Availability Cluster MultiProcessing.
HAL		Hard Array Logic.
HAL             Hardware Abstraction Layer.
HAL       	House programmed Array Logic.
HAL     	Heuristically Programmed Algorithmic computer. From 1968 movie 
		"2001: A Space Odyssey".
HAR		Host Audit Record.
HASP      	Houston Automatic Spooling Priority system.
HBA       	Host Bus Adapter.
HCU       	Home Computer User.
HD        	Hard Disk.
HD              Hierarchical Direct.
HD		High Density.
HDA       	Head Disk Assembly.
HDAM            Hierarchical Direct Access Method. An HDAM database consists 
                of a single OSAM or VSAM file. In both HD structures, the
                root segment is accessed by a hash on the sequence field.
HDCD      	High Definition Compatible Digital.
HDDL            Hierarchical Data Definition Language.
HDF       	Hierarchical Data Format.
HDI       	Head to Disk Interference.
HDLC            High level Data Link Control. A standard protocol developed
                by the International Standards Organization for software
                applications and communicating devices operating in
                synchronous environments. The protocol defines operations at
                the link level of communications, for example, the format of
                the data frames exchanged between modems over a phone line.
HDML            Hierarchical Data Manipulation Language.
HDR             HeaDeR label.
HDSC      	High Density Signal Carrier.
HDSL      	High-rate Digital Subscriber Link.
HDTV      	High Definition TeleVision.
HDW       	HarDWare.
HDX       	Half DupleX.
HeNCE           Heterogeneous Network Computing Environment. Planned
                additions to PVM include assistance for algorithm
                partitioning and scheduling, support for automatic
                compilation for different architectures, a graphical user
                interface, and debugging and execution-history trace
                facilities. These functions are being developed for PVM under
                a program at Oak Ridge National Laboratory named HeNCE.
HERC      	HERCules.
HEX       	HEXadecimal.
HFS       	Hierarchical File System.
HGA       	Hercules Graphics Adapter.
HGC             Hercules Graphics Controller. A monochrome video adapter
                capable of 720x352 monochrome graphics.  The HGC was the
                first non-IBM video adapter for the IBM PC.  See also CGA,
                MDA.
HGCP      	Hercules Graphics Card Plus.
HH        	Hour.
HIDAM           Hierarchical Indexed Direct Access Method. A HIDAM database
                consist of two parts: an index database and a "data"
                database. The data database is a single OSAM or VSAM
                (entry-sequenced data set) file consisting of fixed-length
                records that are initially loaded in hierarchical sequence.
                It is treated as an HDAM database itself.
HIFD      	High-Density Floppy Disk.
HIL       	Human Interface Link.
HIMEM     	HIgh MEMory.
HIPAC           HIgh Performance ACtive database system. HIPAC was a research
                effort focussing on active time-constrained data management.
HIPO            Hierarchical Input Process Output. This is a diagrammatic
                method for organizing and presenting information-processing
                requirements.
HIPPI     	High Performance Parallel Interface.
HISAM           Hierarchical Indexed Sequential Access Method. In the HISAM
                organization, the database consists of two files or storage
                areas or data sets : one file (prime area) contains root
                segments (plus some additional segments that fit within the
                record in that file); another file (overflow area) contains
                the remaining tail portion of each linearized tree.
HLCO      	High Low Close Open.
HLL             High-Level Logic.
HLLAPI    	High Level Language Application Programming Interface.
.HLP      	HeLP. File name extension.
HLQ       	High Level Qualifier.
HLS       	Hue, Luminance, Saturation. Color model.
HLT       	HaLT.
HMA             High Memory Area. The first 65520 bytes (64K less 16 bytes)
                of extended memory. This area is accessible from real mode on
                the 80286 and higher processors because these processors do
                not wrap addresses at one megabyte as the 8088 and 8086 do.
HMA		Hub Management Architecture.
HMD       	Head Mounted Display.
HMOS      	High density Metal Oxide Semiconductor.
HMOS          	High Speed Metal Oxide Semiconductor.
HMP       	Host Monitoring Protocol.
HOTT      	Hot Off The Tree. Electronic newsletter.
HP              Hewlett-Packard.
HPC             High-Performance Computing.
HPCC      	High Performance Computing and Communications.
HPCN            High-Performance Computing and Networking.
HPDJ      	Hewlett-Packard Desk Jet.
HPF             High Performance Fortran.
HPFS            High Performance File System. OS/1.2 introduces the HPFS as
                the replacement to the MS-DOS FAT file system. HPFS as three
                distinct parts: a new means of organizing data on the hard
                disk, conversion of applications program file requests into
                hard disk device driver commands, and implementation of
                installable file systems.
HPG       	Hewlett-Packard Graphics.
HPGL		Hewlett-Packard Graphics Language.
HPIB      	Hewlett-Packard Interface Bus.
HPLJ      	Hewlett-Packard Laser Jet.
HPPA      	Hewlett-Packard Precision Architecture.
HPPI      	High Performance Parallel Interface.
HPR       	High Performance Routing.
HP-THT          High-Priority Token Hold Timer.
HP-UX           Hewlett-Packard-UniX.
HPW       	High Performance Workstation.
.HQX      	BinHexed. File name extension.
HRIS      	Human Resource Information System.
HRG       	High Resolution Graphics.
HRMS      	Human Resource Management System.
HS              Hierarchical Sequential.
HSA             Hardware-System Architecture. The design of the hardware
                system of a computer, including its central processing unit,
                dataflow organization, bus structure, control organization
                and input-output system.
HSAM            Hierarchical Sequential Access Method. HSAM ties together the
                segments within a tree by physical contiguity. The trees
                themselves are placed in physical sequence in storage. Each
                physical database record represents one occurrence tree. HSAM
                "strings out" the physical records sequentially, in order of
                the sequence key of the root segment, with a fixed block size.
HSC       	High Speed Channel.
HSI       	Hue Saturation Intensity.
HSM             Hiererchical Storage Management.
HSM             High Speed Memory.
HSP             High Speed Printer.
HSSI      	High Speed Serial Interface.
HST             High Speed Technology. USRobotics' proprietary signaling
                scheme, design and error control protocol for high-speed
                modems. HST incorporates trellis-coded modulation, for
                greater immunity from variable phone line conditions, and 
                asymmetrical modulation for more efficient use of the phone
                channel at speeds of 4800 BPS and above. HST also 
                incorporates MNP-compatible error control procedures adapted 
                to asymmetrical modulation.
.HST      	HiSTory. File name extensions.
HST		HoST. File name extensions.
HSV       	Hue Saturation Value.
HTML            HyperText Markup Language. HTML is a SGML DTD. In practical 
                terms HTML is a collection of styles (indicated by markup 
                tags) that define the various components of a WWW document.
HTTP            HyperText Transport Protocol.
HURD            Heads Up Range Device.
HUT       	Hopkins Ultraviolet Telescope.
H/V       	Horizontal/Vertical.
HVP       	Horizontal & Vertical Position.
H/W       	HardWare.
HWCP      	HardWare Code Page.
HWD       	Height-Width-Depth.
.HYP      	HYPhenation. File name extension.
HYTELNET  	HYpertext-browser for TELNET accessible sites.
Hz              Hertz. Frequency in cycles per second of a musical note or
                ratio wave. One cycle equals one Hertz. Average human range
                is from 20 Hz to 20000 Hz. Also a frequency measurement unit
                used internationally to indicate one cycle per second.
