A microprogramming teaching environment is presented. It is composed of a hardware part (a 16 bit microprogrammable processor) and a software part, running on a Macintosh II computer. The software includes 6 modules: two microassemblers - one uses a classical approach to generate microcode from a description in a register transfer language and the other one, which is more unusual, is menu-driven -; a disassembler; a monitor allowing one to display and modify the processor resources, as well as to control the execution; a memory loader and a simulator. The interactive and convivial nature of the Macintosh computer, and especially the HyperCard application, are used thoroughly in order to facilitate a utilization of the system.