\setlength{\unitlength}{0.0125in}%
\begin{picture}(360,172)(9,624)
\thicklines
\put( 91,719){\circle{24}}
\put(140,719){\circle{24}}
\put(189,719){\circle{24}}
\put(287,719){\circle{24}}
\multiput(222,719)(12.80000,0.00000){3}{\line( 1, 0){  6.400}}
\put(201,719){\line( 1, 0){ 21}}
\put(254,719){\vector( 1, 0){ 21}}
\multiput(222,759)(7.11111,0.00000){5}{\line( 1, 0){  3.556}}
\multiput(222,784)(7.11111,0.00000){5}{\line( 1, 0){  3.556}}
\put(262,784){\line(-1, 0){  8}}
\put(262,759){\line(-1, 0){  8}}
\put(213,759){\line( 1, 0){  9}}
\put(213,784){\line( 1, 0){  9}}
\put(332,653){\framebox(25,24){}}
\put( 21,759){\framebox(29,25){}}
\put(  9,624){\framebox(360,172){}}
\put(299,719){\line( 1, 0){ 45}}
\put(344,719){\line( 0, 1){  0}}
\put(344,719){\vector( 0,-1){ 42}}
\put(287,759){\vector( 0,-1){ 29}}
\put(152,719){\vector( 1, 0){ 25}}
\put(103,719){\vector( 1, 0){ 24}}
\put( 34,759){\line( 0,-1){ 40}}
\put( 34,719){\vector( 1, 0){ 45}}
\put(189,759){\vector( 0,-1){ 29}}
\put(140,759){\vector( 0,-1){ 29}}
\put( 91,759){\vector( 0,-1){ 29}}
\put(262,759){\framebox(50,25){}}
\put( 66,759){\framebox(147,25){}}
\put(165,784){\line( 0,-1){ 25}}
\put(115,784){\line( 0,-1){ 25}}
\put( 82,726){\line( 1,-1){ 16.500}}
\put( 82,710){\line( 1, 1){ 16.500}}
\put(132,710){\line( 1, 1){ 16}}
\put(132,726){\line( 1,-1){ 16}}
\put(181,726){\line( 1,-1){ 16}}
\put(181,710){\line( 1, 1){ 16}}
\put(279,710){\line( 1, 1){ 16.500}}
\put(279,726){\line( 1,-1){ 16.500}}
\put(336,661){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm acc'}}}
\put(279,767){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm xn}}}
\put(185,767){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm x3}}}
\put(136,767){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm x2}}}
\put( 87,767){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm x1}}}
\put( 25,767){\makebox(0,0)[lb]{\raisebox{0pt}[0pt][0pt]{\tenrm acc}}}
\end{picture}
