diff --git a/decstates.v b/decstates.v
index 0cce0fb..8c34c8c 100644
--- a/decstates.v
+++ b/decstates.v
@@ -17,8 +17,9 @@
 `define DEC_LC_LEN          21      //  3n...
 `define DEC_LC              22      //  3n[x]
 `define DEC_GOTO            30      //  6
-`define DEC_GOTO_LOOP       31      //  6[x]
-`define DEC_GOTO_EXEC       32      //  6xxx -> exec
+`define DEC_GOTO_LOOP       31      //  6[x] -> exec
+`define DEC_GOSUB           32      //  7
+`define DEC_GOSUB_LOOP      33      //  7[x] -> exec
 `define DEC_8X              40      //  8X
 `define DEC_80X             41      //  80X
 `define DEC_CONFIG          42      //  805
@@ -37,5 +38,6 @@
 `define DEC_AaX_EXEC        71      //  Aax
 `define DEC_AbX_EXEC        72      //  Abx
 `define DEC_BX              80      //  Bx
+`define DEC_DX             100      //  Dx
 
 `endif
\ No newline at end of file
diff --git a/opcodes/7xxx_GOSUB.v b/opcodes/7xxx_GOSUB.v
new file mode 100644
index 0000000..147ccbb
--- /dev/null
+++ b/opcodes/7xxx_GOSUB.v
@@ -0,0 +1,34 @@
+/******************************************************************************
+ * 6xxx			GOSUB 		xxx
+ *
+ *
+ */ 
+
+`include "decstates.v"
+`include "bus_commands.v"
+
+`DEC_GOSUB: begin
+    //$display("DEC_GOTO : nibble %h", nibble);
+    jump_offset <= 0;
+    t_cnt <= 2;
+    t_ctr <= 1;
+    jump_offset[3:0] <= nibble;
+    rstk_ptr <= rstk_ptr + 1;
+    decstate <= `DEC_GOSUB_LOOP;
+end
+`DEC_GOSUB_LOOP: begin
+    $display("PC %h | t_cnt %d | t_ctr %d | jump_offset %h", PC, t_cnt, t_ctr, jump_offset);
+    jump_offset[t_ctr*4+:4] <= nibble;
+    if (t_ctr == t_cnt) begin
+        new_PC <= PC + 1 + {8'h00, nibble, jump_offset[7:0]};
+        next_cycle <= `BUSCMD_LOAD_PC;
+        decstate <= `DEC_START;
+        RSTK[rstk_ptr] <= PC + 1;
+`ifdef SIM
+        $display("%5h GOSUB\t%3h\t=> %05h", 
+            inst_start_PC, 
+            {nibble, jump_offset[7:0]}, 
+            PC + 1 + {8'h00, nibble, jump_offset[7:0]});
+`endif
+    end else t_ctr <= t_ctr + 1;
+end