CP/M-86

CP/M-86 was a version of the CP/M operating system that Digital Research made for the Intel 8086 and Intel 8088. The commands are those of CP/M-80. Executable files used the relocatable .CMD file format. It was later reworked to become MS-DOS compatible and renamed to DR-DOS.

CP/M-86 and the IBM PC

When IBM contacted other companies to obtain components for the IBM PC, the as-yet unreleased CP/M-86 was its first choice for an operating system because CP/M had the most applications at the time. Negotiations between Digital Research and IBM quickly deteriorated over IBM's non-disclosure agreement and its insistence on a one-time fee rather than DRI's usual royalty licensing plan. [cite book
last = Freiberger
first = Paul
coauthors = and Michael Swaine
title = Fire in the Valley: The Making of the Personal Computer
origyear = 1984
url = http://www.fireinthevalley.com/
edition = 2nd edition
year = 2000
publisher = McGraw-Hill
location = New York
id = ISBN 0-07-135892-7
pages = pp. 332-333 ] After discussions with Microsoft, IBM decided to use 86-DOS (QDOS), a CP/M-like operating system that a Seattle area computer company had made for its own hardware. Microsoft adapted 86-DOS for the PC hardware and IBM shipped it as PC-DOS.

After learning about the deal, Digital Research founder Gary Kildall threatened to sue IBM for infringing DRI's intellectual property, and IBM agreed to offer CP/M-86 on the PC to settle the claim. CP/M-86 was released a few months after the PC and was one of three operating systems a customer could buy from IBM. At $240 per copy it sold poorly compared to the $40 PC-DOS. Kildall would later accuse IBM of setting the prices to marginalize him, but the accounts of Microsoft, IBM, and other DRI executives indicate that Kildall had demanded a substantial royalty for CP/M-86 while Microsoft had accepted a fixed sum. Customers rapidly adopted the PC platform with PC-DOS as the new industry standard, and opportunities for DRI to license CP/M-86 to other customers dwindled.

Versions

A given version of CP/M-86 will have two version numbers. One applies to the whole system and is usually displayed at startup; the other applies to the BDOS kernel. Versions known to exist include:

* CP/M-86 for the IBM Personal Computer Version 1.0 (BDOS 2.2) - January 1982 - Initial release for the IBM PC.
* CP/M-86 for the IBM Personal Computer Version 1.1 (BDOS 2.2) - March 1983 - Hard drive support was added.
* Personal CP/M-86 Version 1.0 (BDOS 3.1) - November 1983 - Released for the Siemens PG685. Based on the multitasking Concurrent CP/M kernel, it could run up to four tasks at once.
* Personal CP/M-86 Version 3.1 (BDOS 3.3) - January 1985 - A version for the Apricot F-Series computers. This version gained the ability to use MS-DOS formatted disks.
* Personal CP/M-86 Version 2.0 (BDOS 4.1) - 1986 or later - Released for the Siemens PC16-20. This is the same BDOS used in DOS Plus.
* Personal CP/M-86 Version 2.11 (BDOS 4.1) - 1986 or later - Released for the Siemens PG685.

It is believed that the various Personal CP/M-86 versions were based on an unreleased product known as "CP/M-86 Plus"; all known Personal CP/M-86 versions contain this string.

See also

* History of computing hardware (1960s-present)

References

External links

* [http://www.discoverpotsdam.com/~cpm86/ CP/M-86 Resource Library]
* [http://www.cpm.z80.de/ The Unofficial CP/M Website] , which has a licence from the copyright holder to distribute original Digital Research software.
* [http://www.faqs.org/faqs/CPM-faq/ The comp.os.cpm FAQ]