diff --git a/common/place.cc b/common/place.cc
new file mode 100644
index 00000000..d3348820
--- /dev/null
+++ b/common/place.cc
@@ -0,0 +1,82 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include <iostream>
+#include <ostream>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <vector>
+#include <list>
+#include <map>
+#include <set>
+
+#include "log.h"
+#include "design.h"
+
+namespace Placer {
+};
+
+void place_design(Design *design) {
+	std::set<IdString>		types_used;
+	std::set<IdString>::iterator	not_found, element;
+	std::set<BelType>		used_bels;
+
+	for(auto cell_entry : design->cells) {
+		CellInfo	*cell = cell_entry.second;
+		BelType		bel_type;
+
+		element = types_used.find(cell->type);
+		if (element != types_used.end()) {
+			continue;
+		}
+
+		bel_type = belTypeFromId(cell->type);
+		if (bel_type == TYPE_NIL) {
+			log_error("No Bel of type \'%s\' defined for "
+				"this chip\n", cell->type.c_str());
+		}
+		types_used.insert(cell->type);
+		std::cout << cell->type << std::endl;
+	}
+
+	for(auto bel_type_name : types_used) {
+		BelRange	blist = design->chip.getBels();
+		BelType		bel_type = belTypeFromId(bel_type_name);
+		BelIterator	bi = blist.begin();
+
+		for(auto cell_entry : design->cells) {
+			CellInfo	*cell = cell_entry.second;
+
+			// Only place one type of Bel at a time
+			if (cell->type.compare(bel_type_name)!=0)
+				continue;
+
+			while((bi != blist.end())
+					&&(design->chip.getBelType(*bi) != bel_type))
+				bi++;
+			if (bi == blist.end())
+				log_error("Too many \'%s\' used in design\n",
+					cell->type.c_str());
+			cell->bel = *bi++;
+		}
+	}
+}
+
diff --git a/common/rulecheck.cc b/common/rulecheck.cc
index 28d4b6b7..11e57b8b 100644
--- a/common/rulecheck.cc
+++ b/common/rulecheck.cc
@@ -21,12 +21,17 @@ bool	check_all_nets_driven(Design *design) {
 				port_entry.first.c_str(),
 				port.name.c_str());
 			assert(port.name.compare(port_entry.first)==0);
-			assert(port.net);
 			assert(port.name.size() > 0);
-			if (debug) log_info("    Checking for a net named \'%s\'\n",
-				port.net->name.c_str());
-			assert(design->nets.count(port.net->name)>0);
-			// assert(design->nets[port.net->name]->driver.cell);
+
+			if (port.net == NULL) {
+				if (debug) log_warning("    Port \'%s\' in cell \'%s\' is unconnected\n",
+					port.name.c_str(), cell->name.c_str());
+			} else {
+				assert(port.net);
+				if (debug) log_info("    Checking for a net named \'%s\'\n",
+					port.net->name.c_str());
+				assert(design->nets.count(port.net->name)>0);
+			}
 		}
 	}
 
diff --git a/frontend/json/jsonparse.cc b/frontend/json/jsonparse.cc
index 41ecebd4..3d7c52ea 100644
--- a/frontend/json/jsonparse.cc
+++ b/frontend/json/jsonparse.cc
@@ -413,7 +413,25 @@ void	json_import_cell_ports(Design *design, string &modname, CellInfo *cell,
 	is_bus = (wire_group_node->data_array.size()>1);
 
 	// Now loop through all of the connections to this port.
-	for(int index=0; index < wire_group_node->data_array.size(); index++) {
+	if (wire_group_node->data_array.size() == 0) {
+		//
+		// There is/are no connections to this port.
+		//
+		// Create the port, but leave the net NULL
+		PortInfo	this_port;
+
+		//
+		this_port.name = port_info.name;
+		this_port.type = port_info.type;
+		this_port.net = NULL;
+
+		cell->ports[this_port.name] = this_port;
+
+		if (json_debug) log_info("      Port \'%s\' has no connection in \'%s\'\n",
+			this_port.name.c_str(), cell->name.c_str());
+
+	} else for(int index=0; index < wire_group_node->data_array.size();
+			index++) {
 		//
 		JsonNode	*wire_node;
 		PortInfo	this_port;
diff --git a/ice40/chip.h b/ice40/chip.h
index 695eea48..dd00c7c8 100644
--- a/ice40/chip.h
+++ b/ice40/chip.h
@@ -276,12 +276,23 @@ struct BelIterator
 {
     int cursor;
 
-    void operator++() { cursor++; }
+    BelIterator operator++() { cursor++; return *this; }
+    BelIterator operator++(int) {
+		BelIterator	prior(*this);
+		cursor++;
+		return prior;
+	}
+
     bool operator!=(const BelIterator &other) const
     {
         return cursor != other.cursor;
     }
 
+    bool operator==(const BelIterator &other) const
+    {
+        return cursor == other.cursor;
+    }
+
     BelId operator*() const
     {
         BelId ret;