C++: A Dialog Programming with the C++ Standard Library

Using the 16-bit Register Names

Before we took this detour into the binary and hexadecimal number systems, I promised to explain what it means to say that the instructions using the 16-bit register names “behave exactly as though they were accessing the 16-bit registers on earlier machines”. After a bit more preparation, we'll be ready for that explanation.

First, let's take a look at some characteristics of the human-readable version of machine instructions: assembly language instructions. The assembly language instructions we will look at have a fairly simple format.^[33] The name of the operation is given first, followed by one or more spaces. The next element is the “destination”, which is the register or RAM location that will be affected ...