Thirty years ago, on July 27 1981, Microsoft bought the rights for QDOS (Quick and Dirty Operating System) from Seattle Computer Products (SCP) for $25,000. QDOS, otherwise known as 86-DOS, was designed by SCP to run on the Intel 8086 processor, and was originally thrown together in just two months for a 0.1 release in 1980. Microsoft bought all rights to 86-DOS from Seattle Computer Products, initially for an additional $50,000 and favorable licenses for Microsoft. After settling a 1986 SCP lawsuit, the total cost to Microsoft was $1 million.

Thirty years ago, I was daily in a cubicle selling auto parts over the telephone. The company used a $50,000 Hewlett Packard 3000 mid-range system powered by a 200MHz PA-8200 RISC processor. In a 50 foot by 50 foot room (2500 sq ft, 232m2), with a huge air conditioner, five people spent all day inputting parts and accounting information. I could walk over to one of the work stations and look up two day old information. Then I would wonder where in the process the order really was.
 
Commodore VIC 20 Computer
Commodore VIC 20 Computer – still works to this date.

At home, there was a Commodore VIC-20 and a friend had a CP/M-based Osborne 1 which is considered to be the first true portable computer. The VIC 20 still works when we turn it on.

Osborne 1 "Laptop" i.e. portable computer
Osborne 1 "Laptop" i.e. world’s first portable computer (no, it wasn’t Compaq)

In 1984, for nearly $6,000, we bought a Compaq 8088 Deskpro Model 3 with 256KB of RAM, two 5 1/4-inch floppies and a ten MegaByte hard drive. It ran Compaq’s version of Microsoft MS-DOS 2.1 operating system. We immediately upgraded to 640k of RAM. Next came a $7,000 Compaq 80286 "luggable" that I used for four years while demonstrating various software I was selling then. That one ran Compaq’s version of Microsoft DOS 3.1. We still have them and they will work when you plug them in.

Novell DOS 7 - One of victims of unformal Microsoft-Intel allianceMicrosoft continued to develop MS-DOS with a number of different versions over the years and while there were competitors that released their own DOS-based operating systems none of them seriously competed with Microsoft’s OS.

In 1985, Microsoft developed the first generation of Windows graphical interface which is now seen on over 90 per cent of the personal computers in the world. One of the better competitors for Microsoft MS-DOS was Novell DOS. However, Microsoft and Intel built compilers that deliberately didn’t recognize the Novell DOS. So eventually the old personal computer competitor was Apple.

Is Microsoft the best operating system? Probably not for specific applications. However, for average general use computing ? running the hundreds of thousands of applications on the various versions of MS-DOS and Windows ? it meets the majority of our needs.

Wikipedia has an interesting step-by-step graphic showing the 30 year development of MS-DOS.

In retrospect, what would we do differently if we could turn the clock back thirty years? Definitely invest $5,000 each in the companies of Microsoft, Intel, Compaq, and Apple. Today, what would our fantasy portfolio look like? I?ve already created mine. If you?ll create yours, in another 30 years we can compare and see which fantasy pays off.