diff --git a/app/assets/javascripts/ansi-interpreter.js.coffee b/app/assets/javascripts/ansi-interpreter.js.coffee
index eab440e..d3a0c04 100644
--- a/app/assets/javascripts/ansi-interpreter.js.coffee
+++ b/app/assets/javascripts/ansi-interpreter.js.coffee
@@ -120,6 +120,8 @@ class AsciiIo.AnsiInterpreter
         @terminal.eraseInLine @n or 0
       when "L"
         @terminal.insertLines @cursorY, @n or 1
+      when "M"
+        @terminal.deleteLines @cursorY, @n or 1
       when "d" # VPA - Vertical Position Absolute
         @terminal.setCursorLine(@n)
       when "l" # l, Reset mode
diff --git a/app/assets/javascripts/terminal.js.coffee b/app/assets/javascripts/terminal.js.coffee
index dc00508..3d8c07f 100644
--- a/app/assets/javascripts/terminal.js.coffee
+++ b/app/assets/javascripts/terminal.js.coffee
@@ -264,7 +264,17 @@ class AsciiIo.Terminal
       @clearLineData l
       i++
 
+    # trim lineData to max size
     @lineData.length = @lines
+
+    @updateScreen()
+
+  deleteLines: (l, n) ->
+    @lineData.splice l, n
+
+    # expand lineData to max size
+    @lineData.length = @lines
+
     @updateScreen()
 
   fill: (line, col, n, char) ->