diff --git a/unireader.lua b/unireader.lua
new file mode 100644
index 000000000..ec766c578
--- /dev/null
+++ b/unireader.lua
@@ -0,0 +1,465 @@
+require "keys"
+require "settings"
+require "selectmenu"
+
+UniReader = {
+	-- "constants":
+	ZOOM_BY_VALUE = 0,
+	ZOOM_FIT_TO_PAGE = -1,
+	ZOOM_FIT_TO_PAGE_WIDTH = -2,
+	ZOOM_FIT_TO_PAGE_HEIGHT = -3,
+	ZOOM_FIT_TO_CONTENT = -4,
+	ZOOM_FIT_TO_CONTENT_WIDTH = -5,
+	ZOOM_FIT_TO_CONTENT_HEIGHT = -6,
+	ZOOM_FIT_TO_CONTENT_HALF_WIDTH = -7,
+
+	GAMMA_NO_GAMMA = 1.0,
+
+	-- framebuffer update policy state:
+	rcount = 5,
+	rcountmax = 5,
+
+	-- zoom state:
+	globalzoom = 1.0,
+	globalzoommode = -1, -- ZOOM_FIT_TO_PAGE
+
+	globalrotate = 0,
+
+	-- gamma setting:
+	globalgamma = 1.0,   -- GAMMA_NO_GAMMA
+
+	-- size of current page for current zoom level in pixels
+	fullwidth = 0,
+	fullheight = 0,
+	offset_x = 0,
+	offset_y = 0,
+	min_offset_x = 0,
+	min_offset_y = 0,
+
+	-- set panning distance
+	shift_x = 100,
+	shift_y = 50,
+	pan_by_page = false, -- using shift_[xy] or width/height
+	pan_x = 0, -- top-left offset of page when pan activated
+	pan_y = 0,
+	pan_margin = 20,
+
+	-- the document:
+	doc = nil,
+	-- the document's setting store:
+	settings = nil,
+
+	-- we will use this one often, so keep it "static":
+	--nulldc = pdf.newDC(),
+	nulldc = nil, -- you have to initialize it in specific reader
+
+	-- tile cache configuration:
+	cache_max_memsize = 1024*1024*5, -- 5MB tile cache
+	cache_item_max_pixels = 1024*1024*2, -- max. size of rendered tiles
+	cache_max_ttl = 20, -- time to live
+	-- tile cache state:
+	cache_current_memsize = 0,
+	cache = {},
+	jump_stack = {},
+}
+
+function UniReader:new(o)
+	o = o or {}
+	setmetatable(o, self)
+	self.__index = self
+	return o
+end
+
+function UniReader:init()
+	print("empty initialization method!")
+end
+
+-- guarantee that we have enough memory in cache
+function UniReader:cacheclaim(size)
+	if(size > self.cache_max_memsize) then
+		-- we're not allowed to claim this much at all
+		error("too much memory claimed")
+		return false
+	end
+	while self.cache_current_memsize + size > self.cache_max_memsize do
+		-- repeat this until we have enough free memory
+		for k, _ in pairs(self.cache) do
+			if self.cache[k].ttl > 0 then
+				-- reduce ttl
+				self.cache[k].ttl = self.cache[k].ttl - 1
+			else
+				-- cache slot is at end of life, so kick it out
+				self.cache_current_memsize = self.cache_current_memsize - self.cache[k].size
+				self.cache[k] = nil
+			end
+		end
+	end
+	self.cache_current_memsize = self.cache_current_memsize + size
+	return true
+end
+
+function UniReader:draworcache(no, zoom, offset_x, offset_y, width, height, gamma, rotate)
+	-- hash draw state
+	local hash = self:cachehash(no, zoom, offset_x, offset_y, width, height, gamma, rotate)
+	if self.cache[hash] == nil then
+		-- not in cache, so prepare cache slot...
+		self:cacheclaim(width * height / 2);
+		self.cache[hash] = {
+			ttl = self.cache_max_ttl,
+			size = width * height / 2,
+			bb = Blitbuffer.new(width, height)
+		}
+		-- and draw the page
+		local page = self.doc:openPage(no)
+		local dc = self:setzoom(page, hash)
+		page:draw(dc, self.cache[hash].bb, 0, 0)
+		page:close()
+	else
+		-- we have the page in our cache,
+		-- so give it more ttl.
+		self.cache[hash].ttl = self.cache_max_ttl
+	end
+	return hash
+end
+
+-- calculate a hash for our current state
+function UniReader:cachehash(no, zoom, offset_x, offset_y, width, height, gamma, rotate)
+	-- TODO (?): make this a "real" hash...
+	return no..'_'..zoom..'_'..offset_x..','..offset_y..'-'..width..'x'..height..'_'..gamma..'_'..rotate
+end
+
+-- blank the cache
+function UniReader:clearcache()
+	self.cache = {}
+	self.cache_current_memsize = 0
+end
+
+-- open a file and its settings store
+function UniReader:open(filename, password)
+	return false
+end
+
+-- set viewer state according to zoom state
+function UniReader:setzoom(page)
+	return nil
+end
+
+-- render and blit a page
+function UniReader:show(no)
+	local slot
+	if self.globalzoommode ~= self.ZOOM_BY_VALUE then
+		slot = self:draworcache(no,self.globalzoommode,self.offset_x,self.offset_y,width,height,self.globalgamma,self.globalrotate)
+	else
+		slot = self:draworcache(no,self.globalzoom,self.offset_x,self.offset_y,width,height,self.globalgamma,self.globalrotate)
+	end
+	fb.bb:blitFullFrom(self.cache[slot].bb)
+	if self.rcount == self.rcountmax then
+		print("full refresh")
+		self.rcount = 1
+		fb:refresh(0)
+	else
+		print("partial refresh")
+		self.rcount = self.rcount + 1
+		fb:refresh(1)
+	end
+	self.slot_visible = slot;
+end
+
+function UniReader:add_jump(pageno)
+	local jump_item = nil
+	-- add current page to jump_stack if no in
+	for _t,_v in ipairs(self.jump_stack) do
+		if _v.page == pageno then
+			jump_item = _v
+			table.remove(self.jump_stack, _t)
+		elseif _v.page == no then
+			-- the page we jumped to should not be show in stack
+			table.remove(self.jump_stack, _t)
+		end
+	end
+	-- create a new one if not found
+	if not jump_item then
+		jump_item = {
+			page = pageno,
+			datetime = os.date("%Y-%m-%d %H:%M:%S"),
+		}
+	end
+	-- insert at the start
+	table.insert(self.jump_stack, 1, jump_item)
+	if #self.jump_stack > 10 then
+		-- remove the last element to keep the size less than 10
+		table.remove(self.jump_stack)
+	end
+end
+
+-- change current page and cache next page after rendering
+function UniReader:goto(no)
+	if no < 1 or no > self.doc:getPages() then
+		return
+	end
+
+	-- for jump_stack
+	if self.pageno and math.abs(self.pageno - no) > 1 then
+		self:add_jump(self.pageno)
+	end
+
+	self.pageno = no
+	self:show(no)
+	if no < self.doc:getPages() then
+		if self.globalzoommode ~= self.ZOOM_BY_VALUE then
+			-- pre-cache next page
+			self:draworcache(no+1,self.globalzoommode,self.offset_x,self.offset_y,width,height,self.globalgamma,self.globalrotate)
+		else
+			self:draworcache(no,self.globalzoom,self.offset_x,self.offset_y,width,height,self.globalgamma,self.globalrotate)
+		end
+	end
+end
+
+-- adjust global gamma setting
+function UniReader:modify_gamma(factor)
+	print("modify_gamma, gamma="..self.globalgamma.." factor="..factor)
+	self.globalgamma = self.globalgamma * factor;
+	self:goto(self.pageno)
+end
+
+-- adjust zoom state and trigger re-rendering
+function UniReader:setglobalzoommode(newzoommode)
+	if self.globalzoommode ~= newzoommode then
+		self.globalzoommode = newzoommode
+		self:goto(self.pageno)
+	end
+end
+
+-- adjust zoom state and trigger re-rendering
+function UniReader:setglobalzoom(zoom)
+	if self.globalzoom ~= zoom then
+		self.globalzoommode = self.ZOOM_BY_VALUE
+		self.globalzoom = zoom
+		self:goto(self.pageno)
+	end
+end
+
+function UniReader:setrotate(rotate)
+	self.globalrotate = rotate
+	self:goto(self.pageno)
+end
+
+function UniReader:showTOC()
+	toc = self.doc:getTOC()
+	local menu_items = {}
+	-- build menu items
+	for _k,_v in ipairs(toc) do
+		table.insert(menu_items,
+		("        "):rep(_v.depth-1).._v.title)
+	end
+	toc_menu = SelectMenu:new{
+		menu_title = "Table of Contents",
+		item_array = menu_items,
+		no_item_msg = "This document does not have a Table of Contents.",
+	}
+	item_no = toc_menu:choose(0, fb.bb:getHeight())
+	if item_no then
+		self:goto(toc[item_no].page)
+	else
+		self:goto(self.pageno)
+	end
+end
+
+function UniReader:showJumpStack()
+	local menu_items = {}
+	for _k,_v in ipairs(self.jump_stack) do
+		table.insert(menu_items, 
+			_v.datetime.." -> Page ".._v.page)
+	end
+	jump_menu = SelectMenu:new{
+		menu_title = "Jump Keeper      (current page: "..self.pageno..")", 
+		item_array = menu_items,
+		no_item_msg = "No jump history.",
+	}
+	item_no = jump_menu:choose(0, fb.bb:getHeight())
+	if item_no then
+		local jump_item = self.jump_stack[item_no]
+		self:goto(jump_item.page)
+	else
+		self:goto(self.pageno)
+	end
+end
+
+
+-- wait for input and handle it
+function UniReader:inputloop()
+	while 1 do
+		local ev = input.waitForEvent()
+		ev.code = adjustKeyEvents(ev)
+		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
+			local secs, usecs = util.gettime()
+			if ev.code == KEY_PGFWD or ev.code == KEY_LPGFWD then
+				if Keys.shiftmode then
+					self:setglobalzoom(self.globalzoom+0.2)
+				elseif Keys.altmode then
+					self:setglobalzoom(self.globalzoom+0.1)
+				else
+					if self.pan_by_page then
+						self.offset_x = self.pan_x
+						self.offset_y = self.pan_y
+					end
+					self:goto(self.pageno + 1)
+				end
+			elseif ev.code == KEY_PGBCK or ev.code == KEY_LPGBCK then
+				if Keys.shiftmode then
+					self:setglobalzoom(self.globalzoom-0.2)
+				elseif Keys.altmode then
+					self:setglobalzoom(self.globalzoom-0.1)
+				else
+					if self.pan_by_page then
+						self.offset_x = self.pan_x
+						self.offset_y = self.pan_y
+					end
+					self:goto(self.pageno - 1)
+				end
+			elseif ev.code == KEY_BACK then
+				if Keys.altmode then
+					-- altmode, exit reader
+					self:clearcache()
+					if self.doc ~= nil then
+						self.doc:close()
+					end
+					if self.settings ~= nil then
+						self.settings:savesetting("last_page", self.pageno)
+						self.settings:savesetting("gamma", self.globalgamma)
+						self.settings:close()
+					end
+					return
+				else
+					-- not altmode, back to last jump
+					if #self.jump_stack ~= 0 then
+						self:goto(self.jump_stack[1].page)
+					end
+				end
+			elseif ev.code == KEY_VPLUS then
+				self:modify_gamma( 1.25 )
+			elseif ev.code == KEY_VMINUS then
+				self:modify_gamma( 0.8 )
+			elseif ev.code == KEY_A then
+				if Keys.shiftmode then
+					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT)
+				else
+					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE)
+				end
+			elseif ev.code == KEY_S then
+				if Keys.shiftmode then
+					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_WIDTH)
+				else
+					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE_WIDTH)
+				end
+			elseif ev.code == KEY_D then
+				if Keys.shiftmode then
+					self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_HEIGHT)
+				else
+					self:setglobalzoommode(self.ZOOM_FIT_TO_PAGE_HEIGHT)
+				end
+			elseif ev.code == KEY_F then
+				self:setglobalzoommode(self.ZOOM_FIT_TO_CONTENT_HALF_WIDTH)
+			elseif ev.code == KEY_T then
+				self:showTOC()
+			elseif ev.code == KEY_B then
+				if Keys.shiftmode then
+					self:add_jump(self.pageno)
+				else
+					self:showJumpStack()
+				end
+			elseif ev.code == KEY_J then
+				self:setrotate( self.globalrotate + 10 )
+			elseif ev.code == KEY_K then
+				self:setrotate( self.globalrotate - 10 )
+			end
+
+			if self.globalzoommode == self.ZOOM_BY_VALUE then
+				local x
+				local y
+
+				if Keys.shiftmode then -- shift always moves in small steps
+					x = self.shift_x / 2
+					y = self.shift_y / 2
+				elseif Keys.altmode then
+					x = self.shift_x / 5
+					y = self.shift_y / 5
+				elseif self.pan_by_page then
+					x = width;
+					y = height - self.pan_margin; -- overlap for lines which didn't fit
+				else
+					x = self.shift_x
+					y = self.shift_y
+				end
+
+				print("offset "..self.offset_x.."*"..self.offset_x.." shift "..x.."*"..y.." globalzoom="..self.globalzoom)
+				local old_offset_x = self.offset_x
+				local old_offset_y = self.offset_y
+
+				if ev.code == KEY_FW_LEFT then
+					self.offset_x = self.offset_x + x
+					if self.offset_x > 0 then
+						self.offset_x = 0
+						if self.pan_by_page and self.pageno > 1 then
+							self.offset_x = self.pan_x
+							self.offset_y = self.min_offset_y -- bottom
+							self:goto(self.pageno - 1)
+						end
+					end
+					if self.pan_by_page then
+						self.offset_y = self.min_offset_y
+					end
+				elseif ev.code == KEY_FW_RIGHT then
+					self.offset_x = self.offset_x - x
+					if self.offset_x < self.min_offset_x then
+						self.offset_x = self.min_offset_x
+						if self.pan_by_page and self.pageno < self.doc:getPages() then
+							self.offset_x = self.pan_x
+							self.offset_y = self.pan_y
+							self:goto(self.pageno + 1)
+						end
+					end
+					if self.pan_by_page then
+						self.offset_y = self.pan_y
+					end
+				elseif ev.code == KEY_FW_UP then
+					self.offset_y = self.offset_y + y
+					if self.offset_y > 0 then
+						self.offset_y = 0
+					end
+				elseif ev.code == KEY_FW_DOWN then
+					self.offset_y = self.offset_y - y
+					if self.offset_y < self.min_offset_y then
+						self.offset_y = self.min_offset_y
+					end
+				elseif ev.code == KEY_FW_PRESS then
+					if Keys.shiftmode then
+						if self.pan_by_page then
+							self.offset_x = self.pan_x
+							self.offset_y = self.pan_y
+						else
+							self.offset_x = 0
+							self.offset_y = 0
+						end
+					else
+						self.pan_by_page = not self.pan_by_page
+						if self.pan_by_page then
+							self.pan_x = self.offset_x
+							self.pan_y = self.offset_y
+						end
+					end
+				end
+				if old_offset_x ~= self.offset_x
+				or old_offset_y ~= self.offset_y then
+						self:goto(self.pageno)
+				end
+			end
+
+			local nsecs, nusecs = util.gettime()
+			local dur = (nsecs - secs) * 1000000 + nusecs - usecs
+			print("E: T="..ev.type.." V="..ev.value.." C="..ev.code.." DUR="..dur)
+		end
+	end
+end
+
+