+ # move lines upwards (arg is how far)
+ # this obliterates the line under the cursor and arg-1 following it
+ csi_M: (lines) ->
+ lines = parseInt @fix_esc_arg lines, '1'
+
+ rearrange = (a) =>
+ return [
+ a[0 ... @y]..., # keep everything above cursor
+ a[@y + lines .. @scroll_bottom]..., # lines we're moving up
+ a[@y ... @y + lines]..., # recycle these
+ a[@scroll_bottom + 1 ... @height]... # keep the rest
+ ]
+ @text = rearrange @text
+ @attributes = rearrange @attributes
+
+ # clear the lines we're recycling
+ for y in [@scroll_bottom - lines + 1 .. @scroll_bottom]
+ for x in [0...@width]
+ @text[y][x] = ' '
+ @attributes[y][x] = 0x07
+