During the transition from the mainframe to the personal computers, the programmers faced several challenging tasks which, at that time, were not possible to solve within the context of higher-level programming languages. Among them were that the input to a mainframe computer was not by using a CRT the monitor, by via a punched tape or a stack of punched cards. Another major problem was the formatting of output from compilers which could parse commands for control of line printers, but not for the control of laser printers. These tasks required the use of the assembly langue libraries, one of which, included in the Microsoft reference manual for its programming languages and used, among others, by programmers at NASA, U.S. Navy, and Armco Corporation, is described in this book.