HDOS is an early
microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
, originally written for the
Heathkit H8
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.
The main diffe ...
computer system and later also available for the
Heathkit H89
The Z-89 is a personal computer produced by Zenith Data Systems (ZDS) in the early 1980s.
Description
The Zenith Z-89 is based on the Zilog Z80 microprocessor running at 2.048 MHz, and supports the HDOS and CP/M operating systems. The ...
and
Zenith Z-89
The Z-89 is a personal computer produced by Zenith Data Systems (ZDS) in the early 1980s.
Description
The Zenith Z-89 is based on the Zilog Z80 microprocessor running at 2.048 MHz, and supports the HDOS and CP/M operating systems. Th ...
computers. The author was
Heath Company employee
Gordon Letwin, who later was an early employee of
Microsoft
Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation producing Software, computer software, consumer electronics, personal computers, and related services headquartered at th ...
and lead architect of
OS/2
OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...
.
HDOS originally came with a limited set of system software tools, including an
assembler
Assembler may refer to:
Arts and media
* Nobukazu Takemura, avant-garde electronic musician, stage name Assembler
* Assemblers, a fictional race in the ''Star Wars'' universe
* Assemblers, an alternative name of the superhero group Champions of A ...
, 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 driver
In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and o ...
s to achieve a degree of device independence and extensibility. Device names followed the
RSX-11
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 ...
-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
In computing, source code, or simply code, is any collection of code, with or without comment (computer programming), comments, written using a human-readable programming language, usually as plain text. The source code of a Computer program, p ...
for HDOS.
The full source paper listing is held at yesterpc.org, old computer museum. Item references (Heathkit part number) are HOS-1-SL part number 595–2466.
Commands
The following list of
command
Command may refer to:
Computing
* Command (computing), a statement in a computer language
* COMMAND.COM, the default operating system shell and command-line interpreter for DOS
* Command key, a modifier key on Apple Macintosh computer keyboards
...
s are supported by HDOS.
* BOOT
* BYE
*
CAT
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...
*
COPY
*
DATE
*
DELETE
* DISMOUNT
* FLAGS
*
HELP
*
MOUNT
Mount is often used as part of the name of specific mountains, e.g. Mount Everest.
Mount or Mounts may also refer to:
Places
* Mount, Cornwall, a village in Warleggan parish, England
* Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, ...
* ONECOPY
*
PIP
*
RENAME
Rename may refer to:
* Rename (computing), rename of a file on a computer
* RENAME (command), command to rename a file in various operating systems
* Rename (relational algebra), unary operation in relational algebra
* Company renaming, rename ...
* RUN
* SET
* STAT
* STATUS
*
TYPE
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* Ty ...
*
VER
Versions
*HDOS 1.0 – written in 1978 by J. Gordon Letwin
*HDOS 1.5 – Gregg Chandler
*HDOS 1.6 – Gregg Chandler
*HDOS 2.0 – released in 1980, written by Gregg Chandler, released into the public domain in April 1988
*HDOS 3.0 – released into the public domain in August 1986
*HDOS 3.02 – enhanced version by Richard Musgrave
HeathDOS
See also
*Heathkit
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, amate ...
*Zenith Data Systems
Zenith Data Systems (ZDS) was a division of Zenith Electronics founded in 1979 after Zenith acquired the Heath Company, which had entered the personal computer market in 1977. Headquartered in Benton Harbor, Michigan, Zenith sold personal compu ...
*List of operating systems
This is a list of operating systems. Computer operating systems can be categorized by technology, ownership, licensing, working state, usage, and by many other characteristics. In practice, many of these groupings may overlap. Criteria for inclusio ...
References
External links
HeathDOSMichael A. Pechuria, Comparing Two Microcomputer Operating Systems: CP/M and HDOS. Communications of the ACM, March 1983, vol. 26, no. 3.
A web site dedicated to preserving the Heathkit 8-bit computers, source listing in PDF form
{{Operating system
Free software operating systems
Public-domain software with source code
1978 software