diff --git a/sentinel65x/PLL.bsv b/hardware/sentinel65x/PLL.bsv
similarity index 100%
rename from sentinel65x/PLL.bsv
rename to hardware/sentinel65x/PLL.bsv
diff --git a/sentinel65x/PLL.v b/hardware/sentinel65x/PLL.v
similarity index 100%
rename from sentinel65x/PLL.v
rename to hardware/sentinel65x/PLL.v
diff --git a/hardware/sentinel65x/Top.bsv b/hardware/sentinel65x/Top.bsv
new file mode 100644
index 0000000..dafcac3
--- /dev/null
+++ b/hardware/sentinel65x/Top.bsv
@@ -0,0 +1,57 @@
+package Top;
+
+import Connectable::*;
+import TriState::*;
+
+import ClockOut::*;
+import PLL::*;
+
+interface SystemBus;
+   (* always_enabled,prefix="" *)
+   method Action addr(UInt#(24) addr);
+   (* always_enabled,prefix="" *)
+   method Action phi2(bit phi2);
+   (* always_enabled,prefix="" *)
+   method Action write(bit we);
+endinterface
+
+module mkSystemBus(SystemBus);
+
+endmodule
+
+interface Top;
+   (* always_ready *)
+   method bit clkout();
+
+   interface SystemBus cpu;
+endinterface
+
+(* synthesize,no_default_clock,no_default_reset,default_gate_unused *)
+module mkTop(Clock clk_ref,
+             (* clocked_by="no_clock" *) Reset rst,
+             (* clocked_by="no_clock" *) Inout#(Bit#(8)) data,
+             Top ifc);
+   let pll <- mkPLL(clk_ref);
+   let cpu_clk <- mkClockOut(clocked_by(pll.cpu_clk), reset_by(rst));
+
+   Reg#(Bool) data_out_en <- mkReg(False, clocked_by(pll.cpu_clk), reset_by(rst));
+   Reg#(Bit#(8)) data_out <- mkReg(0, clocked_by(pll.cpu_clk), reset_by(rst));
+   TriState#(Bit#(8)) data_in <- mkTriState(data_out_en, data_out, clocked_by(pll.cpu_clk), reset_by(rst));
+   mkConnection(data, data_in.io);
+
+   interface SystemBus cpu;
+      method clkout = cpu_clk.value;
+      method Action addr(a);
+         noAction;
+      endmethod
+      method Action phi2(v);
+         noAction;
+      endmethod
+      method Action write(bit we);
+         noAction;
+      endmethod
+      //interface data = data_in.io;
+   endinterface
+endmodule
+
+endpackage