Z-DOS is a discontinued
OEM
An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...
version of
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...
's
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft 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 ope ...
specifically adapted to run on the hardware of the
Zenith Z-100
The Z-100 computer is a personal computer made by Zenith Data Systems (ZDS). It was a competitor to the IBM PC.
Design
The Zenith Data Systems Z-100 is a pre-assembled version of the Heathkit H100 electronic kit. In the same family, the Z-120 is ...
personal computer.
Z-100 at old-computers.com
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Overview
The Z-100 used a 8086-family microprocessor, (the Intel 8088
The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers an ...
), but otherwise had a completely different internal architecture from the IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
.
At the time Microsoft's MS-DOS wasn't specifically geared to any specific hardware platform, but could be tailored to run on most any system as long as it used a 8086
The 8086 (also called iAPX 86) is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus (allowi ...
-compatible microprocessor, a situation completely like with the popular CP/M
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. Initial ...
systems of the time, which typically used a 8080
The Intel 8080 (''"eighty-eighty"'') is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibili ...
-compatible (8080, 8085
The Intel 8085 ("''eighty-eighty-five''") is an 8-bit microprocessor produced by Intel and introduced in March 1976. It is software-binary compatible with the more-famous Intel 8080 with only two minor instructions added to support its added i ...
and Z80
The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were ...
among others) microprocessor. In order to achieve this, MS-DOS, like CP/M, relied on a platform-specific (DOS-)BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the ...
, which had to be written for the target machine, so that the hardware-independent DOS kernel could run on it. Beside IBM's OEM version of MS-DOS released as PC DOS there were dozens of other OEM versions of MS-DOS geared to a specific non-IBM-compatible OEM hardware—among them Zenith's Z-DOS. Only later, when almost 100% IBM-compatible clones became the norm, "MS-DOS" became the generic version which could run on most of them. This generic version of MS-DOS, however, could not run on the older non-IBM-compatible machines like the Z-100.
See also
* DOS API
The DOS API is an API which originated with 86-DOS and is used in MS-DOS/ PC DOS and other DOS-compatible operating systems. Most calls to the DOS API are invoked using software interrupt 21h ( INT 21h). By calling INT 21h with a subfunctio ...
* Towns OS
The is a Japanese personal computer, built by Fujitsu from February 1989 to the summer of 1997. It started as a proprietary PC variant intended for multimedia applications and PC games, but later became more compatible with IBM PC compatibles. ...
– an MS-DOS adaptation by Fujitsu
is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...
for FM Towns
* List of DOS commands
This article presents a list of commands used by DOS operating systems, especially as used on x86-based IBM PC compatibles (PCs). Other DOS operating systems are not part of the scope of this list.
In DOS, many standard system commands were pro ...
* Timeline of DOS operating systems
This article presents a timeline of events in the history of 16-bit x86 DOS-family disk operating systems from 1980 to present. Non-x86 operating systems named "DOS" are not part of the scope of this timeline.
Also presented is a timeline of ...
References
{{Disk operating systems
Disk operating systems
DOS variants
Floppy disk-based operating systems