Tanenbaum–Torvalds debate mentioned how he developed Linux specifically for the Intel 80386 because it was partly intended as a learning exercise for Torvalds himself; while he conceded that this made the kernel itself less portable than MINIX, he asserted that this was an acceptable design principle, as it made the application programming interface simpler and more portable. For this reason, he stated, "linux is more portable than minix." Following Linus' reply, Tanenbaum argued that the limitations of MINIX relate to him being a professor, stating the requirement for the system to be able to run on the rather limited hardware of the
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