microsoft was the programmer of ms-dos operating system.
which company was the programmer of ms-dos operating system?
microsoft
microsoft, having worked with scp before and seeking an operating system they could modify for the ibm pc, bought the rights to market the 86-dos operating system to other manufacturers for $25,000 that same month. on july 27, 1981, just prior to the august 12 pc launch, microsoft bought the full rights to the operating system for an additional $50,000, giving scp a perpetual royalty-free license to sell 86-dos (including updated versions) with its computer hardware. realizing that microsoft was making significant profit on the 86-dos operating system, scp attempted to sell it along with a stand-alone inexpensive cpu (without any other circuitry). this was allowed as per scp's license with microsoft, which let scp sell the operating system with their 8086-based computers; this operating system was marketed as "seattle dos", and a cpu was included in the box it shipped in.
seattle computer products
originally ms-dos was designed to be an operating system that could run on "any" computer with a 8086-family microprocessor. it competed with other operating systems written for such computers, such as cp/m-86 and ucsd pascal. each computer would have its own distinct hardware and its own version of ms-dos, a situation similar to the one that existed for cp/m, with ms-dos emulating the same solution as cp/m to adapt for different hardware platforms. so there were many different original equipment manufacturer (oem) versions of "ms-dos" for different hardware. but the greater speed attainable by direct control of hardware was of particular importance, especially when running computer games. so very soon an ibm-compatible architecture became the goal, and before long all 8086-family computers closely emulated ibm hardware, and only a single version of ms-dos for a fixed hardware platform was all that was needed for the market. this specific version of ms-dos is the version that is discussed here, as all other versions of ms-dos died out with their respective systems. one version of such a "generic ms-dos" (z-dos) is mentioned here, but there were dozens more. all these were for personal computers that used an 8086-family microprocessor, but which were not fully ibm pc compatible.
comparison of dos operating systems