diff --git a/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt b/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt
index e8cb045..f013e83 100644
--- a/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt
+++ b/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt
@@ -7,7 +7,7 @@ import sun.nio.ch.DirectBuffer
 class GraphicsJSR223Delegate(val vm: VM) {
 
     private fun getFirstGPU(): GraphicsAdapter? {
-        return vm.peripheralTable[vm.findPeribyType("gpu") ?: return null].peripheral as? GraphicsAdapter
+        return vm.findPeribyType(VM.PERITYPE_TERM)?.peripheral as? GraphicsAdapter
     }
 
     fun resetPalette() {
diff --git a/src/net/torvald/tsvm/VM.kt b/src/net/torvald/tsvm/VM.kt
index 8a718e7..278888d 100644
--- a/src/net/torvald/tsvm/VM.kt
+++ b/src/net/torvald/tsvm/VM.kt
@@ -7,6 +7,8 @@ import net.torvald.tsvm.firmware.Firmware.Companion.toLuaValue
 import net.torvald.tsvm.peripheral.IOSpace
 import net.torvald.tsvm.peripheral.PeriBase
 import org.luaj.vm2.LuaValue
+import java.io.InputStream
+import java.io.OutputStream
 import java.util.*
 import kotlin.math.ceil
 import kotlin.random.Random
@@ -64,6 +66,10 @@ class VM(
 
     val peripheralTable = Array(8) { PeripheralEntry() }
 
+    lateinit var printStream: OutputStream
+    lateinit var errorStream: OutputStream
+    lateinit var inputStream: InputStream
+
     init {
         peripheralTable[0] = PeripheralEntry(
             "io",
@@ -77,9 +83,9 @@ class VM(
     }
 
 
-    fun findPeribyType(searchTerm: String): Int? {
+    fun findPeribyType(searchTerm: String): PeripheralEntry? {
         for (i in 0..7) {
-            if (peripheralTable[i].type == searchTerm) return i
+            if (peripheralTable[i].type == searchTerm) return peripheralTable[i]
         }
         return null
     }
@@ -100,7 +106,7 @@ class VM(
         val HW_RESERVE_SIZE = 1024.kB()
         val USER_SPACE_SIZE = 8192.kB()
 
-        const val PERITYPE_GRAPHICS = "gpu"
+        const val PERITYPE_TERM = "gpu"
     }
 
     internal fun translateAddr(addr: Long): Pair<Any?, Long> {
diff --git a/src/net/torvald/tsvm/VMGUI.kt b/src/net/torvald/tsvm/VMGUI.kt
index 9eef719..78606d0 100644
--- a/src/net/torvald/tsvm/VMGUI.kt
+++ b/src/net/torvald/tsvm/VMGUI.kt
@@ -7,8 +7,8 @@ import com.badlogic.gdx.graphics.OrthographicCamera
 import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import kotlinx.coroutines.*
 import net.torvald.tsvm.peripheral.GraphicsAdapter
-import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.suspendCoroutine
+import java.io.InputStream
+import java.io.OutputStream
 
 class VMGUI(val appConfig: LwjglApplicationConfiguration) : ApplicationAdapter() {
 
@@ -28,9 +28,9 @@ class VMGUI(val appConfig: LwjglApplicationConfiguration) : ApplicationAdapter()
         gpu = GraphicsAdapter(lcdMode = false)
 
         vm.peripheralTable[1] = PeripheralEntry(
-            VM.PERITYPE_GRAPHICS,
+            VM.PERITYPE_TERM,
             gpu,
-            256.kB(),
+            GraphicsAdapter.VRAM_SIZE,
             16,
             0
         )
@@ -42,6 +42,9 @@ class VMGUI(val appConfig: LwjglApplicationConfiguration) : ApplicationAdapter()
         batch.projectionMatrix = camera.combined
         Gdx.gl20.glViewport(0, 0, appConfig.width, appConfig.height)
 
+        vm.printStream = gpu.getPrintStream()
+        vm.errorStream = gpu.getErrorStream()
+        //inputStream = gpu.getInputStream()
 
         // TEST PRG
         vmRunner = VMRunnerFactory(vm, "js")
@@ -244,7 +247,7 @@ while (true) {
     for (var k = 0; k < 2560; k++) {
         vm.poke(-(253952 + k + 1) - hwoff, -2); // transparent
         vm.poke(-(253952 + 2560 + k + 1) - hwoff, -1); // white
-        vm.poke(-(253952 + 2560*2 + k + 1) - hwoff, Math.round(Math.random() * 255));
+        /*vm.poke(-(253952 + 2560*2 + k + 1) - hwoff, Math.round(Math.random() * 255));*/
     }
     
     rng = inthash(rng);
@@ -255,7 +258,7 @@ while (true) {
 }
 """.trimIndent()
 
-    private val gpuTestPaletteJs = "eval('${jscode.replace(Regex("//[^\\n]*"), "").replace('\n', ' ')}')"
+    private val gpuTestPaletteJs = "function print(s){vm.print(s)}eval('${jscode.replace(Regex("//[^\\n]*"), "").replace('\n', ' ')}')"
 
 
     private val gpuTestPaletteJava = """
diff --git a/src/net/torvald/tsvm/VMJSR223Delegate.kt b/src/net/torvald/tsvm/VMJSR223Delegate.kt
index 7da90c4..7848c9d 100644
--- a/src/net/torvald/tsvm/VMJSR223Delegate.kt
+++ b/src/net/torvald/tsvm/VMJSR223Delegate.kt
@@ -13,4 +13,13 @@ class VMJSR223Delegate(val vm: VM) {
     fun malloc(size: Int) = vm.malloc(size)
     fun free(ptr: Int) = vm.free(ptr)
 
+    fun print(s: String) {
+        //println("[Nashorn] $s")
+        vm.printStream.write((s + '\n').toByteArray())
+    }
+
+}
+
+class VMSerialDebugger(val vm: VM) {
+    fun print(s: String) = System.out.println(s)
 }
\ No newline at end of file
diff --git a/src/net/torvald/tsvm/VMRunnerFactory.kt b/src/net/torvald/tsvm/VMRunnerFactory.kt
index 0dab64c..a657dbb 100644
--- a/src/net/torvald/tsvm/VMRunnerFactory.kt
+++ b/src/net/torvald/tsvm/VMRunnerFactory.kt
@@ -52,6 +52,7 @@ object VMRunnerFactory {
                         bind.put("graphics", GraphicsJSR223Delegate(vm))
                         //bind.put("poke", { a: Long, b: Byte -> vm.poke(a, b) }) // kts: lambda does not work...
                         //bind.put("nanotime", { System.nanoTime() })
+                        bind.put("serial", VMSerialDebugger(vm))
                     }
 
                     override suspend fun executeCommand(command: String) {
diff --git a/src/net/torvald/tsvm/peripheral/GlassTty.kt b/src/net/torvald/tsvm/peripheral/GlassTty.kt
index fe82d5c..b9c3716 100644
--- a/src/net/torvald/tsvm/peripheral/GlassTty.kt
+++ b/src/net/torvald/tsvm/peripheral/GlassTty.kt
@@ -1,13 +1,27 @@
 package net.torvald.tsvm.peripheral
 
+import java.io.InputStream
+import java.io.OutputStream
 import java.util.*
 
 /**
  * Implements standard TTY that can interpret some of the ANSI escape sequences
+ *
+ * A paper tty must be able to implemented by extending this class (and butchering some of the features), of which it
+ * sets limits on some of the functions (notably 'setCursorPos')
  */
 abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
 
+    /**
+     * (x, y)
+     */
     abstract fun getCursorPos(): Pair<Int, Int>
+
+    /**
+     * Think of it as a real paper tty;
+     * setCursorPos must "wrap" the cursor properly when x-value goes out of screen bound.
+     * For y-value, only when y < 0, set y to zero and don't care about the y-value goes out of bound.
+     */
     abstract fun setCursorPos(x: Int, y: Int)
 
     abstract var rawCursorPos: Int
@@ -19,6 +33,23 @@ abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
 
     abstract fun putChar(x: Int, y: Int, text: Byte, foreColour: Byte = ttyFore.toByte(), backColour: Byte = ttyBack.toByte())
 
+    fun writeOut(char: Byte) {
+        val printable = acceptChar(char)
+
+        if (printable) {
+            val (x, y) = getCursorPos()
+            putChar(x, y, char)
+            setCursorPos(x + 1, y) // should automatically wrap and advance a line for out-of-bound x-value
+        }
+
+        // deal with y-axis out-of-bounds
+        val (cx, cy) = getCursorPos()
+        if (cy >= TEXT_ROWS) {
+            scrollUp(cy - TEXT_ROWS + 1)
+            setCursorPos(cx, TEXT_ROWS - 1)
+        }
+    }
+
     private var ttyEscState = TTY_ESC_STATE.INITIAL
     private val ttyEscArguments = Stack<Int>()
     /**
@@ -52,11 +83,14 @@ abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
 
         when (ttyEscState) {
             TTY_ESC_STATE.INITIAL -> {
-                if (char == ESC) {
-                    ttyEscState = TTY_ESC_STATE.ESC
-                }
-                else {
-                    return true
+                when (char) {
+                    ESC -> ttyEscState = TTY_ESC_STATE.ESC
+                    LF -> crlf()
+                    BS -> backspace()
+                    TAB -> insertTab()
+                    BEL -> ringBell()
+                    in 0x00.toByte()..0x1F.toByte() -> return false
+                    else -> return true
                 }
             }
             TTY_ESC_STATE.ESC -> {
@@ -170,6 +204,8 @@ abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
         return false
     }
 
+
+
     abstract fun resetTtyStatus()
     abstract fun cursorUp(arg: Int = 1)
     abstract fun cursorDown(arg: Int = 1)
@@ -180,15 +216,31 @@ abstract class GlassTty(val TEXT_ROWS: Int, val TEXT_COLS: Int) {
     abstract fun cursorX(arg: Int = 1) // aka Cursor Horizintal Absolute
     abstract fun eraseInDisp(arg: Int = 0)
     abstract fun eraseInLine(arg: Int = 0)
+    /** New lines are added at the bottom */
     abstract fun scrollUp(arg: Int = 1)
+    /** New lines are added at the top */
     abstract fun scrollDown(arg: Int = 1)
     abstract fun sgrOneArg(arg: Int = 0)
     abstract fun sgrTwoArg(arg1: Int, arg2: Int)
     abstract fun sgrThreeArg(arg1: Int, arg2: Int, arg3: Int)
+    /** The values are one-based
+     * @param arg1 y-position (row)
+     * @param arg2 x-position (column) */
     abstract fun cursorXY(arg1: Int, arg2: Int)
     abstract fun ringBell()
     abstract fun insertTab()
+    abstract fun crlf()
+    abstract fun backspace()
 
+    abstract fun getPrintStream(): OutputStream
+    abstract fun getErrorStream(): OutputStream
+    abstract fun getInputStream(): InputStream
+
+    private val CR = 0x0D.toByte()
+    private val LF = 0x0A.toByte()
+    private val TAB = 0x09.toByte()
+    private val BS = 0x08.toByte()
+    private val BEL = 0x07.toByte()
     private val ESC = 0x1B.toByte()
 
     private enum class TTY_ESC_STATE {
diff --git a/src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt b/src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt
index d210e9b..a53332a 100644
--- a/src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt
+++ b/src/net/torvald/tsvm/peripheral/GraphicsAdapter.kt
@@ -9,6 +9,9 @@ import net.torvald.tsvm.AppLoader
 import net.torvald.tsvm.VM
 import net.torvald.tsvm.kB
 import sun.nio.ch.DirectBuffer
+import java.io.InputStream
+import java.io.OutputStream
+import java.io.PrintStream
 import kotlin.experimental.and
 
 class GraphicsAdapter(val lcdMode: Boolean = false) : GlassTty(Companion.TEXT_ROWS, Companion.TEXT_COLS), PeriBase {
@@ -58,8 +61,28 @@ class GraphicsAdapter(val lcdMode: Boolean = false) : GlassTty(Companion.TEXT_RO
         set(value) { spriteAndTextArea.setShort(memTextCursorPosOffset, value.toShort()) }
 
     override fun getCursorPos() = rawCursorPos % TEXT_COLS to rawCursorPos / TEXT_COLS
+    /**
+     * Think of it as a real paper tty;
+     * setCursorPos must "wrap" the cursor properly when x-value goes out of screen bound.
+     * For y-value, only when y < 0, set y to zero and don't care about the y-value goes out of bound.
+     */
     override fun setCursorPos(x: Int, y: Int) {
-        rawCursorPos = toTtyTextOffset(x, y)
+        var newx = x
+        var newy = y
+
+        if (newx >= TEXT_COLS) {
+            newx = 0
+            newy += 1
+        }
+        else if (newx < 0) {
+            newx = 0
+        }
+
+        if (newy < 0) {
+            newy = 0 // DON'T SCROLL when cursor goes ABOVE the screen
+        }
+
+        rawCursorPos = toTtyTextOffset(newx, newy)
     }
     private fun toTtyTextOffset(x: Int, y: Int) = y * TEXT_COLS + x
 
@@ -80,6 +103,7 @@ class GraphicsAdapter(val lcdMode: Boolean = false) : GlassTty(Companion.TEXT_RO
         // -1 is preferred because it points to the colour CLEAR, and it's constant.
         spriteAndTextArea.fillWith(-1)
 
+        setCursorPos(0, 0)
 
         println(framebuffer.pixels.limit())
     }
@@ -194,6 +218,157 @@ class GraphicsAdapter(val lcdMode: Boolean = false) : GlassTty(Companion.TEXT_RO
         spriteAndTextArea[memTextOffset + textOff] = text
     }
 
+    override fun cursorUp(arg: Int) {
+        val (x, y) = getCursorPos()
+        setCursorPos(x, y - arg)
+    }
+
+    override fun cursorDown(arg: Int) {
+        val (x, y) = getCursorPos()
+        val newy = y + arg
+        setCursorPos(x, if (newy >= TEXT_ROWS) TEXT_ROWS - 1 else newy)
+    }
+
+    override fun cursorFwd(arg: Int) {
+        val (x, y) = getCursorPos()
+        setCursorPos(x + arg, y)
+    }
+
+    override fun cursorBack(arg: Int) {
+        val (x, y) = getCursorPos()
+        setCursorPos(x - arg, y)
+    }
+
+    override fun cursorNextLine(arg: Int) {
+        val (_, y) = getCursorPos()
+        val newy = y + arg
+        setCursorPos(0, if (newy >= TEXT_ROWS) TEXT_ROWS - 1 else newy)
+        if (newy >= TEXT_ROWS) {
+            scrollUp(newy - TEXT_ROWS + 1)
+        }
+    }
+
+    override fun cursorPrevLine(arg: Int) {
+        val (_, y) = getCursorPos()
+        setCursorPos(0, y - arg)
+    }
+
+    override fun cursorX(arg: Int) {
+        val (_, y) = getCursorPos()
+        setCursorPos(arg, y)
+    }
+
+    override fun eraseInDisp(arg: Int) {
+        when (arg) {
+            else -> TODO()
+        }
+    }
+
+    override fun eraseInLine(arg: Int) {
+        when (arg) {
+            else -> TODO()
+        }    }
+
+    /** New lines are added at the bottom */
+    override fun scrollUp(arg: Int) {
+        //TODO("Not yet implemented")
+    }
+
+    /** New lines are added at the top */
+    override fun scrollDown(arg: Int) {
+        TODO("Not yet implemented")
+    }
+
+    override fun sgrOneArg(arg: Int) {
+        TODO("Not yet implemented")
+    }
+
+    override fun sgrTwoArg(arg1: Int, arg2: Int) {
+        TODO("Not yet implemented")
+    }
+
+    override fun sgrThreeArg(arg1: Int, arg2: Int, arg3: Int) {
+        TODO("Not yet implemented")
+    }
+
+    /** The values are one-based
+     * @param arg1 y-position (row)
+     * @param arg2 x-position (column) */
+    override fun cursorXY(arg1: Int, arg2: Int) {
+        TODO("Not yet implemented")
+    }
+
+    override fun ringBell() {
+        TODO("Not yet implemented")
+    }
+
+    override fun insertTab() {
+        TODO("Not yet implemented")
+    }
+
+    override fun crlf() {
+        val (_, y) = getCursorPos()
+        val newy = y + 1
+        setCursorPos(0, if (newy >= TEXT_ROWS) TEXT_ROWS - 1 else newy)
+        if (newy >= TEXT_ROWS) scrollUp(1)
+    }
+
+    override fun backspace() {
+        val (x, y) = getCursorPos()
+        putChar(x, y, 0x20.toByte())
+        setCursorPos(x - 1, y)
+    }
+
+    private lateinit var PRINTSTREAM_INSTANCE: OutputStream
+    private lateinit var ERRORSTREAM_INSTANCE: OutputStream
+    private lateinit var INPUTSTREAM_INSTANCE: InputStream
+
+    override fun getPrintStream(): OutputStream {
+        try {
+            return PRINTSTREAM_INSTANCE
+        }
+        catch (e: UninitializedPropertyAccessException) {
+            PRINTSTREAM_INSTANCE = object : OutputStream() {
+                override fun write(p0: Int) {
+                    writeOut(p0.toByte())
+                }
+            }
+
+            return PRINTSTREAM_INSTANCE
+        }
+
+    }
+
+    override fun getErrorStream(): OutputStream {
+        try {
+            return ERRORSTREAM_INSTANCE
+        }
+        catch (e: UninitializedPropertyAccessException) {
+            ERRORSTREAM_INSTANCE = object : OutputStream() {
+                private val SGI_RED = byteArrayOf(0x1B, 0x5B, 0x33, 0x31, 0x6D)
+                private val SGI_RESET = byteArrayOf(0x1B, 0x5B, 0x6D)
+
+                override fun write(p0: Int) {
+                    SGI_RED.forEach { writeOut(it) }
+                    writeOut(p0.toByte())
+                    SGI_RESET.forEach { writeOut(it) }
+                }
+
+                override fun write(p0: ByteArray) {
+                    SGI_RED.forEach { writeOut(it) }
+                    p0.forEach { writeOut(it) }
+                    SGI_RESET.forEach { writeOut(it) }
+                }
+            }
+
+            return ERRORSTREAM_INSTANCE
+        }
+    }
+
+    override fun getInputStream(): InputStream {
+        TODO("Not yet implemented")
+    }
+
     override fun dispose() {
         framebuffer.dispose()
         rendertex.dispose()