Z-DOS is a discontinued OEM version of

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

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 op ...

specifically adapted to run on the hardware of the Zenith Z-100 personal computer.

Overview

Z-DOS is Zenith Data Systems's name for a version of

operating system designed for the Zenith Z-100 computer. The Z-100 uses 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 ...

), but otherwise has 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 List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...

. Microsoft's MS-DOS was not specifically designed to any specific hardware platform, but can be tailored to run on most any system as long as it uses 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 (allo ...

-compatible microprocessor, a situation similar to

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/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...

, which typically uses a

8080 The Intel 8080 is Intel's second 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a weekly trade newspa ...

-compatible (8080, 8085 and

Z80 The Zilog Z80 is an 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be software-compatible with the Intel 8080, offering a compelling altern ...

among others) microprocessor. In order to achieve this, MS-DOS, like CP/M, relies 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 a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...

, which is written for the target machine, so that the hardware-independent DOS kernel can run on it. Beside IBM's OEM version of MS-DOS released as PC DOS there are dozens of other OEM versions of MS-DOS designed for a specific non-IBM-compatible OEM hardware—among them Zenith's Z-DOS. When almost 100% IBM-compatible clones became the norm, "MS-DOS" became the generic version which could run on most of them. Later such generic versions of MS-DOS cannot run on older non-IBM-compatible machines like the Z-100.

References

{{Disk operating systems Disk operating systems Discontinued Microsoft operating systems DOS variants Floppy disk-based operating systems

Overview

See also

References