I use \fbox{} in LaTeX to draw a box around a text. How can one achieve a computer bit representation as shown below,
3 Answers
As mentioned in comments, you should consider, bytefield package for such constructions. It offers many sophisticated layouts out of the box. For more details, type texdoc bytefield from the command line/prompt) or visit texdoc.net. An example (from th manual):
\documentclass{article} \usepackage{bytefield} \begin{document} \begin{bytefield}[endianness=little,bitwidth=0.11111\linewidth]{8} %\bitheader{0-7} \\ \bitbox{1}{Res} & \bitbox{1}{BE} & \bitbox{1}{CF} & \bitbox{3}{$\mbox{Name\_Len}-1$} & \bitbox{2}{Len\_Len} \\ \end{bytefield} \end{document} 
Remarks
Using the almighty tikz I created a command \drawbits, which takes a comma separated list of values, where 0 denotes an unset bit and anything else (e.g. 1) a set bit.
Implementation
\documentclass{article} \pagestyle{empty}%for cropping \usepackage{tikz} \newcommand\drawbits[1]{% \tikz[x=1.5ex,y=1.5ex,every path/.style={draw=black,semithick}]{% \foreach \y [count=\i] in {#1} { \expandafter\ifx\y0 \draw (\i,0) rectangle (\i+1,1); \else \draw (\i,0) rectangle (\i+1,1); \filldraw[fill=black] (\i+0.2,0.2) rectangle (\i*1+0.8,0.8); \fi }% }% } \begin{document} My bits: \drawbits{0,0,1,1,0,1,0} \large My bits: \drawbits{0,0,1,1,0,1,0} \Large My bits: \drawbits{0,0,1,1,0,1,0} \LARGE My bits: \drawbits{0,0,1,1,0,1,0} \end{document} Output
An alternative to the bytefield package is to use the venerable Tikz:
\usepackage{tikz} \newcommand\drawbits[1]{\tikz\draw[step=12pt] (0,0) grid (#1*12pt,12pt);} will load Tikz and define a command called \drawbits that will draw a specified number of bits. For example:
Here are eight bits: \drawbits{8}. produces: 
bytefieldpackage.