Tim Paterson is the original creator of MS-DOS operating system. After graduating magna cum laude in Computer Science in June 1978 from the University of Washington he designed a schematic of Microsoft's Z-80 SoftCard which had a Z80 CPU and ran the CP/M operating system on an Apple II. A month later, with the release of the 8086 CPU, Paterson designed the S-100 8086 board, which could only run a standalone version of Microsoft BASIC, so to compensate he designed QDOS (Quick And Dirty Operating System), which was a rough port of CP/ API code, eventually called 86-DOS.