diff --git a/luprex/cpp/core/drivenengine.cpp b/luprex/cpp/core/drivenengine.cpp
index 62d79fd1..5e2d7b00 100644
--- a/luprex/cpp/core/drivenengine.cpp
+++ b/luprex/cpp/core/drivenengine.cpp
@@ -37,7 +37,9 @@ DrivenEngineInitializerReg::DrivenEngineInitializerReg(DrivenEngineInitializer f
 //////////////////////////////////////////////////////////////////////////////
 
 int DrivenEngine::find_unused_chid() {
-    // Note: channel ID zero is special, it is never reused.
+    // Note: channel ID zero is never used.  Channel ID 0 used to be
+    // reserved for the stdio channel.  When we eliminated the stdio
+    // channel, we blocked off ID 0 permanently.
     for (int i = 0; i < DRV_MAX_CHAN; i++) {
         int id = next_unused_chid_++;
         if (next_unused_chid_ == DRV_MAX_CHAN) next_unused_chid_ = 1;
@@ -48,6 +50,7 @@ int DrivenEngine::find_unused_chid() {
 }
 
 Channel *DrivenEngine::get_chid(int chid) const {
+    assert(chid != 0);
     assert(unsigned(chid) < DRV_MAX_CHAN);
     assert(channels_[chid].get() != nullptr);
     return channels_[chid].get();
@@ -160,10 +163,6 @@ SharedChannel DrivenEngine::new_incoming_channel() {
     }
 }
 
-SharedChannel DrivenEngine::get_stdio_channel() {
-    return stdio_channel_;
-}
-
 void DrivenEngine::set_visible_world_and_actor(World *w, int64_t id) {
     visible_world_ = w;
     visible_actor_id_ = id;
@@ -180,8 +179,6 @@ void DrivenEngine::stop_driver() {
 
 DrivenEngine::DrivenEngine() {
     next_unused_chid_ = 1;
-    stdio_channel_ = eng::make_shared<Channel>(this, 0, 0, "", false);
-    channels_[0] = stdio_channel_;
     rescan_lua_source_ = false;
     clock_ = 0.0;
     have_prints_ = false;
diff --git a/luprex/cpp/core/drivenengine.hpp b/luprex/cpp/core/drivenengine.hpp
index 453987f4..502bef0c 100644
--- a/luprex/cpp/core/drivenengine.hpp
+++ b/luprex/cpp/core/drivenengine.hpp
@@ -196,16 +196,6 @@ public:
     //
     SharedChannel new_incoming_channel();
 
-    // Obtain the stdio channel. There is only one stdio channel.
-    //
-    // DRIVER: the stdio channel is created automatically when the DrivenEngine
-    // is created.  Stdio should be connected to a console which is in
-    // line-at-a-time mode.  The driver is responsible for relaying data from
-    // the console into the stdio channel using drv_peek_outgoing,
-    // drv_sent_outgoing, drv_recv_incoming.
-    //
-    SharedChannel get_stdio_channel();
-    
     // Set the flag to rescan the lua source directory. The lua source
     // directory is read once, automatically, at engine creation time.
     // If you want to read it again, you must trigger a rescan.
@@ -300,7 +290,6 @@ private:
 private:
     SharedChannel channels_[DRV_MAX_CHAN];
     int next_unused_chid_;
-    SharedChannel stdio_channel_;
     eng::vector<SharedChannel> accepted_channels_;
     eng::vector<uint32_t> new_outgoing_;
     eng::vector<uint32_t> listen_ports_;
diff --git a/luprex/cpp/core/eng-tests.cpp b/luprex/cpp/core/eng-tests.cpp
index 42ac95a6..d78d3e44 100644
--- a/luprex/cpp/core/eng-tests.cpp
+++ b/luprex/cpp/core/eng-tests.cpp
@@ -6,19 +6,15 @@
 
 #include <iomanip>
 
-static void write_closed_message(Channel *ch, StreamBuffer *out) {
-    eng::ostringstream oss;
-    oss << "Chan " << ch->chid() << " closed [" << ch->error() << "]\n";
-    out->write_bytes(oss.str());
+static void write_closed_message(Channel *ch) {
+    util::dprint("Chan ", ch->chid(), " closed [", ch->error(), "]\n");
 }
 
-static void dump_lines(StreamBuffer *in, StreamBuffer *out, int chid) {
+static void dump_lines(StreamBuffer *in, int chid) {
     while (true) {
         eng::string l = in->readline();
         if (l == "") break;
-        eng::ostringstream oss;
-        oss << "Chan " << chid << ": " << l;
-        out->write_bytes(oss.str());
+        util::dprint("Chan ", chid, ": ", l);
     }
 }
 
@@ -34,13 +30,11 @@ public:
     }
     
     virtual void event_update() override {
-        SharedChannel stdioch = get_stdio_channel();
-        dump_lines(stdioch->in(), stdioch->out(), 0);
         eng::vector<SharedChannel> keep;
         for (SharedChannel &ch : channels_) {
-            dump_lines(ch->in(), stdioch->out(), ch->chid());
+            dump_lines(ch->in(), ch->chid());
             if (ch->closed()) {
-                write_closed_message(ch.get(), stdioch->out());
+                write_closed_message(ch.get());
             } else {
                 keep.emplace_back(std::move(ch));
             }
@@ -60,13 +54,11 @@ public:
     }
     
     virtual void event_update() override {
-        SharedChannel stdioch = get_stdio_channel();
-        dump_lines(stdioch->in(), stdioch->out(), 0);
         eng::vector<SharedChannel> keep;
         for (SharedChannel &ch : channels_) {
-            dump_lines(ch->in(), stdioch->out(), ch->chid());
+            dump_lines(ch->in(), ch->chid());
             if (ch->closed()) {
-                write_closed_message(ch.get(), stdioch->out());
+                write_closed_message(ch.get());
             } else {
                 keep.emplace_back(std::move(ch));
             }