1. Introduction to MIX

Plain MIX is a set of tools for assembling, running and debugging programs, written in MIXAL, an assembly language for an imaginary computer, MIX, used in “The Art of Computer Programming” of D. Knuth.

This package provides a development platform for those who wish to try out examples and exercises from the book. It includes the following programs:


A MIXAL assembler, i.e. a program which translates a MIXAL source file into a program that can be run on a MIX machine.


MIX machine simulator. There is no real, hardware, MIX machine, but you may use mixsim to emulate it and to run the programs, prepared by mixal. The mixsim utility also provides a terminal mode with a debugger, which is useful for finding and fixing bugs in your programs. It is also handy for educational purposes, as it allows to trace progam execution.


A utility to run MIXAL programs, without creating an intermediate object file.

This manual assumes the reader has some basic notions about MIX and MIXAL and that he has a copy of “The Art of Computer Programming” (referred to in this book as TAOCP) at hand. The page references to TAOCP assume the Addison-Wesley edition, 1968 (Library of congress catalog card no. 67-26020).