diff --git a/erjang_cfg.properties b/erjang_cfg.properties
index 727e6c2d..8b080c18 100644
--- a/erjang_cfg.properties
+++ b/erjang_cfg.properties
@@ -1,6 +1,6 @@
-#erjang.otp.root = /usr/local/lib/erlang
-#erjang.erts.version = 5.8
-#erjang.otp.version = R14B
+erjang.otp.root = /usr/local/lib/erlang
+erjang.erts.version = 5.8.3
+erjang.otp.version = R14B02
 
 # erjang.debug.port=true
 # erjang.debug.inet=true
diff --git a/src/main/java/erjang/ERT.java b/src/main/java/erjang/ERT.java
index 7c3de9e3..37d1d580 100644
--- a/src/main/java/erjang/ERT.java
+++ b/src/main/java/erjang/ERT.java
@@ -21,6 +21,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
@@ -1050,15 +1051,56 @@ public static void shutdown() {
 		async_scheduler.shutdown();
 	}
 
-	static public InputStream orig_in = System.in;
-	static public PrintStream orig_out = System.out;
-	static public PrintStream orig_err = System.err;
+	static protected volatile InputStream in = System.in;
+	static protected volatile PrintStream out = System.out;
+	static protected volatile PrintStream err = System.err;
 	
 	public static void set_stdio(InputStream in,
 			PrintStream out, PrintStream err) {
-		System.setIn(in);
-		System.setOut(out);
-		System.setErr(err);
+		// avoid null
+		ERT.in = (in != null ? in : new NullInputStream());
+		ERT.out = (out != null ? out : new PrintStream(new NullOutputStream()));
+		ERT.err = (err != null ? err : new PrintStream(new NullOutputStream()));
+	}
+
+	public static void set_stdio(InputStream in,
+			OutputStream out, OutputStream err) {
+		// avoid null
+		ERT.in = (in != null ? in : new NullInputStream());
+		ERT.out = (out != null ? new PrintStream(out) : new PrintStream(new NullOutputStream()));
+		ERT.err = (err != null ? new PrintStream(err) : new PrintStream(new NullOutputStream()));
+	}
+
+	public static void setInputStream(InputStream in) {
+		ERT.in = (in != null ? in : new NullInputStream());
+	}
+
+	public static InputStream getInputStream() {
+		return in;
+	}
+
+	public static void setOutputStream(PrintStream out) {
+		ERT.out = (out != null ? out : new PrintStream(new NullOutputStream()));
+	}
+
+	public static void setOutputStream(OutputStream out) {
+		ERT.out = (out != null ? new PrintStream(out) : new PrintStream(new NullOutputStream()));
+	}
+
+	public static PrintStream getOutputStream() {
+		return out;
+	}
+
+	public static void setErrorStream(PrintStream err) {
+		ERT.err = (err != null ? err : new PrintStream(new NullOutputStream()));
+	}
+
+	public static void setErrorStream(OutputStream err) {
+		ERT.err = (err != null ? new PrintStream(err) : new PrintStream(new NullOutputStream()));
+	}
+
+	public static PrintStream getErrorStream() {
+		return err;
 	}
 
 	public static File newFile(String file_name) {
@@ -1077,4 +1119,26 @@ public static void debug(boolean condition, String text) {
 			debug(text);
 		}
 	}
+	
+	static class NullInputStream extends InputStream {
+		@Override
+		public int read() throws IOException {
+			return -1;
+		}
+	}
+	static class NullOutputStream extends OutputStream {
+		@Override
+		public void write(int arg0) throws IOException {
+			// ignore
+		}
+		@Override
+		public void write(byte[] b) throws IOException {
+			// ignore
+		}
+		@Override
+		public void write(byte[] b, int off, int len) throws IOException {
+			// ignore
+		}
+	}
+
 }
diff --git a/src/main/java/erjang/console/TTYTextAreaDriverControl.java b/src/main/java/erjang/console/TTYTextAreaDriverControl.java
index 4d32ec76..c65938de 100644
--- a/src/main/java/erjang/console/TTYTextAreaDriverControl.java
+++ b/src/main/java/erjang/console/TTYTextAreaDriverControl.java
@@ -47,6 +47,7 @@
 import erjang.EHandle;
 import erjang.EObject;
 import erjang.EPID;
+import erjang.ERT;
 import erjang.EString;
 import erjang.driver.EDriverInstance;
 import erjang.driver.IO;
@@ -157,7 +158,7 @@ public void replace(DocumentFilter.FilterBypass fb,
 	}
 
 	public InputStream getInputStream() {
-		return System.in;
+		return ERT.getInputStream();
 	}
 
 	public OutputStream getOutputStream() {
diff --git a/src/main/java/erjang/driver/FDDriverInstance.java b/src/main/java/erjang/driver/FDDriverInstance.java
index bb80038b..efd51686 100644
--- a/src/main/java/erjang/driver/FDDriverInstance.java
+++ b/src/main/java/erjang/driver/FDDriverInstance.java
@@ -60,15 +60,15 @@ public FDDriverInstance(int in, int out) {
 		this.out = out;
 		
 		if (in == 0) {
-			ins = System.in;
+			ins = ERT.getInputStream();
 		} 
 		
 		if (out == 1) {
-			outs = System.out;
+			outs = ERT.getOutputStream();
 		}
 		
 		if (out == 2) {
-			outs = System.err;
+			outs = ERT.getErrorStream();
 		}
 		// that's it.
 	}
diff --git a/src/main/java/erjang/driver/efile/EFile.java b/src/main/java/erjang/driver/efile/EFile.java
index 86ff32ac..9c15f6c1 100644
--- a/src/main/java/erjang/driver/efile/EFile.java
+++ b/src/main/java/erjang/driver/efile/EFile.java
@@ -1965,7 +1965,7 @@ void reply_list_directory(String[] files) throws Pausable {
 	 * 
 	 * @see http://www.erlang.org/doc/apps/stdlib/unicode_usage.html#id60205
 	 */
-	static boolean unicodeDriverInterface = ("R14B".compareTo(erjang.Main.otp_version) < 0);
+	static boolean unicodeDriverInterface = ("R14B".compareTo(erjang.Main.otp_version == null ? "" : erjang.Main.otp_version) < 0);
 	
 	/**
 	 * Determine whether to use the new unicode driver interface
diff --git a/src/main/java/erjang/m/erlang/ErlProc.java b/src/main/java/erjang/m/erlang/ErlProc.java
index f21a6711..82dd28fe 100644
--- a/src/main/java/erjang/m/erlang/ErlProc.java
+++ b/src/main/java/erjang/m/erlang/ErlProc.java
@@ -120,7 +120,7 @@ public static EObject process_info(EObject pid) {
 
 	@BIF
 	public static EObject display(EProc proc, EObject obj) {
-		System.out.println(obj);
+		ERT.getOutputStream().println(obj);
 		return ERT.TRUE;
 	}
 
diff --git a/src/main/java/erjang/util/Progress.java b/src/main/java/erjang/util/Progress.java
index 9de5af87..5f454c7e 100644
--- a/src/main/java/erjang/util/Progress.java
+++ b/src/main/java/erjang/util/Progress.java
@@ -21,6 +21,8 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import erjang.ERT;
+
 public class Progress {
 	static ProgressListener listener;
 
@@ -47,7 +49,7 @@ static public void activity(String string) {
                 }
 
                 if (!Boolean.parseBoolean(suppress)) {
-				    System.err.write(wheel[next % 4]);
+                	ERT.getErrorStream().write(wheel[next % 4]);
                 }
 			} catch (IOException e) {
 				// ignore