Feeds

Microsoft's MS-DOS is 30 today

Kudos to QDOS

Build a business case: developing custom apps

MS-DOS is 30 years old today. Well, kind of. On 27 July 1981, Microsoft gave the name MS-DOS to the disk operating system it acquired on that day from Seattle Computer Products (SCP), a hardware company owned and run by a fellow called Rod Brock.

SCP developed what it at various times called QDOS and 86-DOS to run on a CPU card it had built based on Intel's 8086 processor.

MS-DOS 1.19

Command line: MS-DOS 1.19 still running after all these years

The company had planned to use Digital Research's CP/M-86 operating system, then still in development. But, having released the card in November 1979 - it shipped with an 8086-compatible version Microsoft's Basic language interpreter-cum-operating system - and reached April 1980 without CP/M-86 becoming available to bundle, SCP decided it had to create its own OS for the card.

Enter, in August 1980, QDOS. It really did stand for Quick and Dirty Operating System. That's actually what it was: a basic but serviceable OS good for coding and running programs written in 8086 assembly language - the x86 instruction set. It was written by SCP's Tim Paterson, who had joined the company as a programmer a couple of years previously and began work on it in April 1980.

Seattle Computer Products Ad

On the cards: Seattle Computer Products advertises its wares

Some observers later claimed that QDOS too closely resembled CP/M for comfort. Paterson himself would later say that QDOS' design criteria specifically included the abililty to support programs written for CP/M and compiled for the 8086. That's not at all surprising given that SCP undoubtedly saw QDOS as a temporary stand in until Digital Research (DR) shipped CP/M-86.

The picture we have today is muddied by the claims that IBM originally wanted to use CP/M-86 in its first personal computer. IBM and DR famously failed to come to terms that would allow CP/M-86 to be bundled with the PC, and IBM turned to Microsoft for an alternative. Digital Research founder Gary Kildall, who died in 1994, would later allege that Microsoft's product was a rip off, fuelling plagiarism claims that Paterson has always denied - he reverse engineered it.

CP/M-86

The competition: CP/M-86 in action
Source: Wikipedia

Update My fellow Reg hack Andrew Orlowski points out that, no matter what Paterson says, the US court ruled against the programmer in a defamation lawsuit he brought against publisher Little Brown for claiming the origins of QDOS were not clear-cut.

Back in 1980, Paterson continued to evolve QDOS through the year, the OS being renamed 86-DOS - it was now evidently no longer viewed as a rough-and-ready stand-in - between September and December 1980. Accounts differ as to when the name - and the OS' status - was switched, but December is the date Paterson himself gave during a Softtalk interview published just a few years later.

Build a business case: developing custom apps

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.