\chapter{Overview} This is an attempt to distill what I know about how computers work into some kind of emulator / simulator. I'm curious to see if what I know at the moment is enough to allow me to emulate a general purpose computer. A computer that will be big-endian, using 8-bit bytes for its char type. The memory is a 32 bit linear address space allowing for a maximum of 2\textsuperscript{32} bytes to be addressable. \section{Registers} Eight 32-bit general purpose registers are available for holding operands and memory addresses along with a Flags Register. The Flags Register is a 32-bit register allowing for 32 flags. Currently there are only arithmetic flags which are Overflow (OF), Underflow (UF), and a Zero Flag (ZF). The overflow flag is set if there is a carry. A base pointer register contains a 32 bit address that points to the start of the current stack frame, which is the first opcode of the stack frame. Therefore the first argument would be addressed as such: \begin{verbatim} mov r1, bp - sizeof(void *) \end{verbatim} Finally we have the Program Counter which contains a 32 bit address that points to the next instruction to execute. \tikzstyle{blockRow} = [rectangle, minimum width=10cm, minimum height=0.5cm, text centered, draw=black] %Note: tikzset might be better to use instead of tikzstyle. \tikzset{ Rect/.style = {rectangle, fill=red!10!white} } \begin{figure}[!htb] %\centering \begin{tikzpicture} \node at (1 ,0) {31}; %\node [Rect] at (0, 2) {test}; %\node at (0, ) \foreach \pos in {1,...,8} { %\node at (0, \pos + 1) [blockRow] (\pos) {\pos}; \node at (0, \pos - 1) [blockRow] {r\pos}; ;} %\node [blockRow] (start) {r1}; %\node (r2) [blockRow] [below=of start] {r2}; \end{tikzpicture} \caption{Register Bit Layout} \end{figure} \section{Memory Layout}