diff --git a/icebox/icebox_hlc2asc.py b/icebox/icebox_hlc2asc.py
index 2c1bc83..f33b2b0 100755
--- a/icebox/icebox_hlc2asc.py
+++ b/icebox/icebox_hlc2asc.py
@@ -293,7 +293,7 @@
         for i, xy in enumerate(GLB_NETWK_INTERNAL_TILES):
             if net == 'glb_netwk_%d' % i and (x, y) == xy:
                 return 'fabout'
-        raise ParseError("{} is a global netowrk, but not at an expectd location {} {}".format(net, x, y))
+        raise ParseError("{} is a global network, but not at an expected location {} {}".format(net, x, y))
 
     return net
 
@@ -990,7 +990,7 @@
         if fields == ['io_1'] and self.blocks[1] is None:
             self.blocks[1] = IOBlock(self, 1)
             return self.blocks[1]
-        raise ParseError("Unepxected new block in {}".format(type(self).__name__))
+        raise ParseError("Unexpected new block in {}".format(type(self).__name__))
 
 class IOBlock:
     def __init__(self, tile, index):
@@ -1040,7 +1040,9 @@
             self.enable_input = True
         elif fields == ['disable_pull_up'] and not self.disable_pull_up:
             self.disable_pull_up = True
-        elif fields[0] == 'GLOBAL_BUFFER_OUTPUT' and fields[1] == '->' \
+        elif fields[0] in ('GLOBAL_BUFFER_OUTPUT',
+                           'io_%d/GLOBAL_BUFFER_OUTPUT' % self.index) \
+                and fields[1] == '->' \
                 and fields[2].startswith('glb_netwk_'):
             if GLB_NETWK_EXTERNAL_BLOCKS[int(fields[2][10:])] \
                     != (self.tile.x, self.tile.y, self.index):
diff --git a/icebox/icebox_vlog.py b/icebox/icebox_vlog.py
index a86f11e..0080f34 100755
--- a/icebox/icebox_vlog.py
+++ b/icebox/icebox_vlog.py
@@ -345,21 +345,21 @@
             else:
                 net_segs.add(s)
 
-    count_drivers = 0
+    count_drivers = []
     for s in segs:
-        if re.match(r"ram/RDATA_", s[2]): count_drivers += 1
-        if re.match(r"io_./D_IN_", s[2]): count_drivers += 1
-        if re.match(r"lutff_./out", s[2]): count_drivers += 1
-        if re.match(r"lutff_./lout", s[2]): count_drivers += 1
+        if re.match(r"ram/RDATA_", s[2]): count_drivers.append(s[2])
+        if re.match(r"io_./D_IN_", s[2]): count_drivers.append(s[2])
+        if re.match(r"lutff_./out", s[2]): count_drivers.append(s[2])
+        if re.match(r"lutff_./lout", s[2]): count_drivers.append(s[2])
 
-    if count_drivers != 1 and check_driver:
-        failed_drivers_check.append(n)
+    if len(count_drivers) != 1 and check_driver:
+        failed_drivers_check.append((n, count_drivers))
 
     if not strip_comments:
         for s in sorted(net_segs):
                 text_wires.append("// %s" % (s,))
         if count_drivers != 1 and check_driver:
-            text_wires.append("// Number of drivers: %d" % count_drivers)
+            text_wires.append("// Number of drivers: %d %s" % (len(count_drivers), count_drivers))
         text_wires.append("")
 
 def seg_to_net(seg, default=None):
@@ -842,9 +842,9 @@
     else:
         always_stmts.append("/* FF %2d %2d %2d */ assign %s = %s;" % (lut[0], lut[1], lut[2], net_out, net_lout))
     if not "1" in lut_bits:
-        const_assigns.append([net_out, "1'b0"])
+        const_assigns.append([net_lout, "/* LUT   %2d %2d %2d */ 1'b0" % (lut[0], lut[1], lut[2])])
     elif not "0" in lut_bits:
-        const_assigns.append([net_out, "1'b1"])
+        const_assigns.append([net_lout, "/* LUT   %2d %2d %2d */ 1'b1" % (lut[0], lut[1], lut[2])])
     else:
         def make_lut_expr(bits, sigs):
             if not sigs:
@@ -941,7 +941,9 @@
 print()
 
 if failed_drivers_check:
-    print("// Single-driver-check failed for %d nets:" % len(failed_drivers_check))
-    print("// %s" % " ".join(failed_drivers_check))
-    assert False
+    emsg = ["Single-driver-check failed for %d nets:" % len(failed_drivers_check)]
+    for net, drivers in failed_drivers_check:
+        emsg.append("%s has %d drivers: %s" % (net, len(drivers), drivers))
+    print("//", "\n//".join(emsg))
+    assert False, "\n  ".join(emsg)