\documentclass{minimal}
\pagestyle{empty}

\usepackage{pstricks}
\usepackage{pst-node}

\begin{document}

\begin{psmatrix}[mnode=oval, colsep=1.95cm, rowsep=1cm]
[mnode=R,name=vars]{\shortstack[l]{int s, z, c,\\\, strich, punkt;\\opcode aktop,opp;}} &
[name=int]{\shortstack{\textbf{int}\\z:=z*10\\+(c-'0');}} &
[name=blank]{\shortstack{\textbf{blank}}} \\
%%
[mnode=R,name=res]{sys\_res} &
[name=sign]{\shortstack{\textbf{sign}\\s:=-1;}} &
[name=null]{\shortstack{\textbf{null}\\aktop:=DONE;}} \\
%%
[name=idle]{\shortstack{\textbf{idle}\\strich:=0;\\punkt:=1;\\opp:=NOP;}} &
[name=read]{\shortstack{\textbf{read char}\\z:=0;\\s:=1;}} &
[name=calc]{
	\shortstack{
		\textbf{calc}\\
		siehe Listing
	}
} \\
%%
[mnode=R,name=void]{} &
[name=err]{\shortstack{\textbf{error}}} &
[name=done]{\shortstack{\textbf{done}}} \\
\end{psmatrix}

\psset{arrows=->, shortput=nab}

\ncline[linestyle=dotted]{res}{idle}
\ncline[linestyle=dotted]{void}{err}
\ncarc[arcangle=0]{done}{idle}
\ncarc[arcangle=0]{err}{idle}

\ncarc[arcangle=0]{idle}{read}\ncput*[npos=.50]{do\_it$\uparrow$}
\nccurve[angleA=45,angleB=75,ncurvA=2,ncurvB=2]{read}{read}\ncput*{' '}
\ncarc[arcangle=0]{read}{sign}\ncput*[npos=.50]{'-'}

\ncarc[arcangle=0]{sign}{int}
\ncarc[arcangle=50]{read}{int}\ncput*[npos=.35]{c = '0'\dots{}'9'}
\nccircle[angleA=0]{int}{.78cm}\ncput*[npos=0.5]{c = '0'\dots{}'9'}

\ncarc[arcangle=15]{int}{blank}\ncput*[npos=.50]{' '}
\nccircle[angleA=0]{blank}{.70cm}\ncput*[npos=0.5]{' '}

\ncarc[arcangle=67]{blank}{calc}\ncput*[npos=.80]{aktop = '+','-','*','/'}
\ncarc[arcangle=0]{blank}{null}\ncput*[npos=.50]{aktop = '\textbackslash 0'}

\ncarc[arcangle=0]{int}{calc}\ncput*[npos=.70]{aktop = '+','-','*','/'}
\ncarc[arcangle=0]{int}{null}\ncput*[npos=.50]{aktop = '\textbackslash 0'}
\ncarc[arcangle=0]{null}{calc}

\ncarc[arcangle=0]{calc}{read}\ncput*[npos=.45]{else}
\ncarc[arcangle=0]{calc}{done}\ncput*[npos=.50]{aktop = DONE}
\end{document}