Linus Torvalds Second Lieutenant, with the role of a ballistic calculation officer. Torvalds bought computer science professor Andrew Tanenbaum's book "", in which Tanenbaum describes MINIX, an educational stripped-down version of Unix. In 1990, he resumed his university studies, and was exposed to UNIX for the first time, in the form of a DEC MicroVAX running ULTRIX. His M.Sc. thesis was titled "Linux: A Portable Operating System". His interest in computers began with a Commodore VIC-20, at the age of 11 in 1981, initially programming in BASIC, but later by directly accessing the 6502 CPU in machine code. He did not make
Operating system ROM and known as "monitors". One notable early disk operating system was CP/M, which was supported on many early microcomputers and was closely imitated by Microsoft's MS-DOS, which became widely popular as the operating system chosen for the IBM PC (IBM's version of it was called IBM DOS or PC DOS). In the 1980s, Apple Computer Inc. (now Apple Inc.) abandoned its popular Apple II series of microcomputers to introduce the Apple Macintosh computer with an innovative graphical user interface (GUI) to the Mac OS. The introduction of the Intel 80386 CPU chip in October 1985, with 32-bit architecture and