KENTAC is a series of mechatronics controllers, named after its designers Kenjo and H. Takahashi. Its most popular commercial model, KENTAC mark2, uses a Z80 central processor and incorporates a versatile operating system, self-assembler software, and utility subroutines for motor control. For students starting out to learn Z-80 programming, the KENTAC numerical keyboard can be used to input machine code directly, debugging, running the program to drive the motor, etc. In practical applications, assembly language programs are entered on a PC terminal (connected via an RS-232C cable) using the built-in communication software/hardware, and the programs are converted to machine code by the KENTAC mark2's assembler. A photograph of the set-up with KENTAC mark2 and ML1 and sample programs are presented in Chapter 7 of Reference .