Added a distinction between constant numbers and what are effectively memory addresses (i.e. strings and labels).

src/opcodes.c

@@ -3,18 +3,45 @@
 #include <string.h>
 
 Instruction instructions[OPCODECOUNT] = {
-    { "copy", COPY, Reg, Reg | Immediate16 },
-    { "add", ADD, Reg, Reg | Immediate16 },
-    { "sub", SUB, Reg, Reg | Immediate16 },
-    { "jz", JZ, Immediate16, None },
-    { "int", INT, Immediate16, None },
+    { "copy", COPY, Reg | Address, Reg | Constant | Address },
+    { "add", ADD, Reg, Reg | Constant },
+    { "sub", SUB, Reg, Reg | Constant },
+    { "jz", JZ, Address, None },
+    { "int", INT, Constant, None },
     { "yld", YLD, None, None },
     { "ret", RET, None, None },
-    { "cmp", CMP, Reg | Immediate16, Reg | Immediate16 },
-    { "in", IN, None, None},
-    { "out", OUT, None, None}
+    { "cmp", CMP, Reg, Reg | Constant },
+    { "in", IN, Constant | Reg, None},
+    { "out", OUT, None, None},
+    { "nop", NOP, None, None}
 };
 
+/*
+    NOP  - 0000 0000
+    JZ   - 0000 0001 JZ Address
+    INT  - 0000 0010 INT Constant
+    YLD  - 0000 0011 YLD
+    RET  - 0000 0100 RET
+    CALL - 0000 0101 CALL Address
+    //IN reads from a port number specified by either a register or a constant.
+    IN   - 0000 0110 IN Constant
+         - 0000 0111 IN REG
+    COPY - 0000 1XXX COPY REG, REG
+         - 0001 0XXX COPY REG, Constant    
+         - 0010 0XXX COPY REG, Address
+         - 0010 1XXX COPY Address, REG
+         - 0011 0XXX COPY Address, Constant
+         - 0011 1XXX COPY Address, Address
+    ADD  - 0100 0XXX ADD REG, REG
+         - 0100 1XXX ADD REG, Constant
+    SUB  - 0101 0XXX SUB REG, REG
+         - 0101 1XXX SUB REG, Constant
+    CMP  - 0110 0XXX CMP REG, REG
+         - 0110 1XXX CMP REG, Constant
+         - 0111 0XXX CMP REG, Address
+    OUT  - 0111 1XXX OUT REG
+*/
+
 Register registers[REGISTERCOUNT] = {
     { "r1", R1 },
     { "r2", R2 },