One of the most overwhelming aspects of the microcomputer revolution has been the speed with which hardware costs have plummeted. The software versus hardware costs ratio which prompted much of the interest in software engineering in recent years has grown dramatically as the parallel development of the microprocessors pushed down the cost of computer systems and their proliferation fueled software demand. This is increasing the need for skilled programmers for microsystems, part of which will be met by programmers currently working on big systems. In this paper we will examine some of the differences in skills and techniques that one can expect to encounter in the transition from programmer to microprogrammer. (The terms microprogram, microprogrammer , and microprogramming are frequently used in reference to the firmware or microcode of large machines. We will be using such terms only with reference to microprocessors.)