| Developer | Heath Company / Gordon Letwin, Richard Musgrave |
|---|---|
| Working state | Discontinued |
| Source model | Open source |
| Initial release | 1978 |
| Latest release | 3.02 |
| Available in | English |
| Platforms | Heathkit H8, Heathkit H89, Zenith Z-89 |
| License | Public domain |
HDOS is an early microcomputer operating system, originally written for the Heathkit H8 computer system and later also available for the Heathkit H89 and Zenith Z-89 computers. The author was Heath Company employee Gordon Letwin, who later was an early employee of Microsoft and lead architect of OS/2.
HDOS originally came with a limited set of system software tools, including an assembler, but many commercial and large set of freeware programs from HUG (Heath User Group) became available for it eventually.
HDOS 2.0 is notable because it was one of the first microcomputer operating systems to use loadable device drivers to achieve a degree of device independence and extensibility. Device names followed the RSX-11-style convention of DKn: where the first two letters were the device driver file name and n was a number (DK0:, DK1:, and so on would all be handled by DK.SYS). Other similarities to RSX included the use of PIP for file transfer, and the use of EOT for file termination.
Similar to how Heath/Zenith published complete schematics and part lists for its computers, the company sold to users the source code for HDOS. [1] [2] Item references (Heathkit part number) are HOS-1-SL part number 595–2466.
Digital Equipment Corporation, using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until he was forced to resign in 1992, after the company had gone into precipitous decline.
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/85-based microcomputers by Gary Kildall of Digital Research, Inc. CP/M is a disk operating system and its purpose is to organize files on a magnetic storage medium, and to load and run programs stored on a disk. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors.
RSX-11 is a discontinued family of multi-user real-time operating systems for PDP-11 computers created by Digital Equipment Corporation. In widespread use through the late 1970s and early 1980s, RSX-11 was influential in the development of later operating systems such as VMS and Windows NT.
RT-11 is a discontinued small, low-end, single-user real-time operating system for the full line of Digital Equipment Corporation PDP-11 16-bit computers. RT-11 was first implemented in 1970. It was widely used for real-time computing systems, process control, and data acquisition across all PDP-11s. It was also used for low-cost general-use computing.
OS/8 is the primary operating system used on the Digital Equipment Corporation's PDP-8 minicomputer.
The Sophisticated Operating System, or SOS, is the primary operating system of the Apple III computer. SOS was developed by Apple Computer and released in October 1980.
GS/OS is an operating system developed by Apple Computer for its Apple IIGS personal computer. It provides facilities for accessing the file system, controlling input/output devices, loading and running program files, and a system allowing programs to handle interrupts and signals. It uses ProDOS as its primary filing system. GS/OS is a component of Apple IIGS System Software versions 4.0 through 6.0.1, and was the first true 16-bit operating system for the IIGS.
Peripheral Interchange Program (PIP) was a utility to transfer files on and between devices on Digital Equipment Corporation's computers. It was first implemented on the PDP-6 architecture by Harrison "Dit" Morse early in the 1960s. It was subsequently implemented for DEC's operating systems for PDP-10, PDP-11, and PDP-8 architectures. In the 1970s and 1980s Digital Research implemented PIP on CP/M and MP/M.
Heathkit is the brand name of kits and other electronic products produced and marketed by the Heath Company. The products over the decades have included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, robots, electronic ignition conversion modules for early model cars with point style ignitions, and the influential Heath H-8, H-89, and H-11 hobbyist computers, which were sold in kit form for assembly by the purchaser.
James Gordon Letwin is an American software developer and one of the eleven early Microsoft employees who posed for an iconic staff portrait taken in Albuquerque in 1978.
Zenith Data Systems Corporation (ZDS) was an American computer systems manufacturing company active from 1979 to 1996. It was originally a division of the Zenith Radio Company, after they had purchased the Heath Company and, by extension, their Heathkit line of electronic kits and kit microcomputers, from Schlumberger in October 1979. ZDS originally operated from Heath's own headquarters in St. Joseph, Michigan. By the time Zenith acquired Heathkit, their H8 kit computer already had an installed fanbase of scientific engineers and computing enthusiasts. ZDS' first offerings were merely preassembled versions of existing Heathkit computers, but within a few years, the company began selling bespoke systems, including the Z-100, which was a hybrid 8085- and 8088-based computer capable of running both CP/M and MS-DOS.
The Z-89 is a personal computer introduced in 1979 by Heathkit, but produced primarily by Zenith Data Systems (ZDS) in the early 1980s. It combined an updated version of the Heathkit H8 microcomputer and H19 terminal in a new case that also provided room for a built-in floppy disk on the right side of the display. Based on the Zilog Z80 microprocessor it is capable of running CP/M as well as Heathkit's own HDOS.
In computing, type is a command in various command-line interpreters (shells) such as COMMAND.COM, cmd.exe, 4DOS/4NT and Windows PowerShell used to display the contents of specified files on the computer terminal. The analogous Unix command is cat.
In computing, help is a command in various command line shells such as COMMAND.COM, cmd.exe, Bash, qshell, 4DOS/4NT, Windows PowerShell, Singularity shell, Python, MATLAB and GNU Octave. It provides online information about available commands and the shell environment.
In computing, copy is a command in various operating systems. The command copies computer files from one directory to another.
Heathkit's H8 is an Intel 8080A-based microcomputer sold in kit form starting in 1977. The H8 is similar to the S-100 bus computers of the era, and like those machines is often used with the CP/M operating system on floppy disk.
MS-DOS is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS". MS-DOS was the main operating system for IBM PC compatibles during the 1980s, from which point it was gradually superseded by operating systems offering a graphical user interface (GUI), in various generations of the graphical Microsoft Windows operating system.
DOS is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible systems from other manufacturers include DR-DOS (1988), ROM-DOS (1989), PTS-DOS (1993), and FreeDOS (1998). MS-DOS dominated the IBM PC compatible market between 1981 and 1995.
Benton Harbor BASIC and Extended Benton Harbor BASIC were two versions of the BASIC programming language written by Heathkit for their H8 microcomputers. The BASICs were patterned on Dartmouth BASIC, and thus differ in some respects from the many Microsoft BASIC clones of the late-1970s era. The two differ from each other in that the former was able to run in machines with only 8 kB of main memory and only supported string constants, while Extended required 12 kB and added string variables and additional features. It is named after the town where Heathkit was located.
