new file mode 100644
--- /dev/null
+++ b/parser/parser.yy
@@ -0,0 +1,84 @@
+/* 
+ *  $Id$
+ * $URL$
+ */
+
+%{
+   #include <stdio.h>
+   #include <ctype.h>
+
+   int regs[26]; 
+   int base;
+	
+   int yyerror();
+   int yylex();
+%}
+
+%start list
+%token DIGIT LETTER
+%left MINUS PLUS MUL DIV
+%left UMINUS
+%%
+
+list : /* empty */ 
+	| list stat '\n' 
+	| list error '\n' { yyerrok; };
+
+stat : 
+	expr { (void) printf( "RESULT: %d\n", $1 ); } 
+	| LETTER '=' expr { regs[$1] = $3; }
+	;
+
+   expr      :  '(' expr ')'
+             {
+                   $$ = $2;
+             }
+             |  expr PLUS expr
+             {
+                   $$ = $1 + $3;
+             }
+             |  expr MINUS expr
+             {
+                   $$ = $1 - $3;
+             }
+             |  expr MUL expr
+             { 
+                   $$ = $1 * $3;
+             }
+             |  expr DIV expr
+             {
+                   $$ = $1 / $3;
+             }
+             |  MINUS expr  %prec UMINUS
+             {
+                   $$ = -$2;
+             }
+             |  LETTER
+             {
+                   $$ = regs[$1];
+             }
+             |  number
+             ;
+
+   number    :   DIGIT
+             {
+                    $$ = $1; base = ($1==0) ? 8 : 10;
+             }
+             |   number DIGIT
+             {
+                    $$ = base * $1 + $2;
+             }
+             ;
+   
+%%
+
+int yyerror() 
+{
+	printf("ERROR\n");
+	return 0;
+}
+
+int yywrap() 
+{
+	return 1;
+}