The IBM 5150 personal computer was powered by an Intel 8088 processor and contained 40K of read-only memory and 16K of user memory. It had 5 expansion slots for extras such as memory and game paddles. Its basic setup cost $1,565 - down from the $9 million cost of a computer two decades before, according to IBM.

Surrpisingly, the personal computer had color/graphics capability. An option was a color monitor with 16 foreground and background colors and 256 characters for text applications.

Other options included a two-direction printer that could print 80 characters per minute and multiple 32K and 64K memory cards that could be plugged into the option slots to increase memory to 256K.

In 1980, after negotiations with Digital Research broke down, IBM contracted a small company called Microsoft to build an operating system for the IBM 5150. Microsoft then purchased a license for 86DOS, aka Quick and Dirty Operating System (QDOS), for $25,000 from Seattle Computer Products in December 1980. It was successfully adapted for the IBM PC. Microsoft then bought full rights to the whole software product in July 1981 for $50,000 and renamed it MS-DOS. IBM licensed the product under the name of PC-DOS in the IBM 5150.

Don Estridge, later called "the father of the PC," led the team at IBM that developed the 5150, the personal computer that sparked the PC revolution.

In 1980 at the age of 24, the "father of DOS" Tim Patterson wrote the Quick and Dirty Operating System or 86DOS for Seattle Computer Products in four months - hence the name. He also helped Microsoft adapt it for the IBM 5150 and worked the first of this three stints with the company from May 1981 to April 1982.

An advertisement for the IBM 5150 noted: "IBM believes that the age of the personal computer has arrived."

IBM sped up development of the 5150 personal computer, worried about the encroachment of the popular Apple II into homes and businesses.

IBM turned to a young company, Microsoft, and its co-founders Paul Allen and Bill Gates, for the operating system for the 5150. This photo was shot shortly after Microsoft signed the contract with IBM. The image was featured in the Seattle Business Journal's October 19, 1981 article, "Building on success, Microsoft owners shoot for $100 million target."

Guess who?

An advertisement for MS-DOS 1.0, the operating system that got its start on the IBM 5150 and was used on the so-called clone PCs.

A typical DOS command.

A DOS memory check.