README assembly

README.md

@@ -1,6 +1,45 @@
 # IN620
+Build and run all examples (pushdown automaton, a<sup>b</sup>, bubble sort, test)  
+```
+make
+```
+build and run specific example  
+```
+make automaton
+make bubble_sort
+make a_pow_b
+make test
+```
+## Assembly
+### registries
++ in : input registry n, n integer (read only)
+	* i@in, i@rn, i@on for indirections  
+	i@rn input registry, address is the integer in rn work registry
++ rn : work registry n, n integer
+	* r@in, r@rn, r@on for indirections
++ on : output registry n, n integer (write only)
+	* o@in, o@rn, o@on for indirections
 	 
-## pushdown automaton
+### arithmetic instructions
++ ADD(r1, r2, r3)
++ SUB(r1, r2, r3)
++ MULT(r1, r2, r3)
++ DIV(r1, r2, r3)  
+
+r3 = r1 OP r2  
+r1, r2 can be integers instead of registries.
+### control instructions
++ JUMP(z)  
+	current instruction += z
++ JE(r1, r2, z)  
+	if r1=r2 then JUMP(z)
++ JL(r1, r2, z)
+	if r1>r2 then JUMP(z)
+
+r3 = r1 OP r2  
+r1, r2 can be integers instead of registries.
+
+## Pushdown automaton
 Input word = i0, I, K  
 + i0 total length of input word
 + I = i1, J