Simple Machine Language interpreter

SML is a "toy" machine language intended to teach basic processor concepts. This website contains an explanation and definition of SML, as well as an interpreter and example SML programs. GPLd source code for the interpreter is available, as well as binaries for Windows and Linux.

A machine language defines a set of instructions that a CPU can execute to perform operations. In other words, a machine language defines what you can do with your computer. Modern processors have very complex instruction sets; however, the simple language described here can give you an understanding of what is happening "under the hood" with your computer.

Machine language is the actual data that is directly run by the processor. Writing a program in machine language can therefore be advantageous if you need to save space or highly optimize your code. However, machine language is also not portable and can be difficult to understand and maintain.

Therefore, almost all code is now written in a higher level language, such as C, C++, Java, or scripting languages such as shell or perl. These languages all have their advantages and disadvantages as well, such as varying levels of portability, maintainability, scalability, and execution speed.

One level higher than machine language is assembly language. Assembly language is basically readable machine language. Instead of writing out the code bit-by-bit, you write out the code as a sequence of human readable instructions, which are then compiled almost directly into machine language.

Assembly language is almost always used instead of machine language when such a direct level of control is needed. For example, some games implement part of their code in assembly in order to maximize execution speed. Assembly can be "inlined" into some higher level languages, like C. This means that the assembly is defined as a callable procedure from within the C code.