The book introduces Pascal and assembler programmers to the possibilities and techniques of low-level programming. Through numerous examples from the practical field of professional software design, it primarily explains areas such as graphics cards, timers, keyboard and memory management, as well as the use of DPMI (DOS Protected Mode Interface), making them accessible to developers. As a special highlight, the book provides readers with an object-oriented toolkit that enables the easy development of user interfaces in graphics mode. The corresponding units, along with all other source codes from the book, are readily available on diskette.