diff --git a/djvu.c b/djvu.c
index 5367efb0e..56a34c32f 100644
--- a/djvu.c
+++ b/djvu.c
@@ -71,7 +71,7 @@ static int handle(lua_State *L, ddjvu_context_t *ctx, int wait)
 
 static int openDocument(lua_State *L) {
 	const char *filename = luaL_checkstring(L, 1);
-	/*const char *password = luaL_checkstring(L, 2);*/
+	int cache_size = luaL_optint(L, 2, 10 << 20);
 
 	DjvuDocument *doc = (DjvuDocument*) lua_newuserdata(L, sizeof(DjvuDocument));
 	luaL_getmetatable(L, "djvudocument");
@@ -82,6 +82,9 @@ static int openDocument(lua_State *L) {
 		return luaL_error(L, "cannot create context.");
 	}
 
+	printf("## cache_size = %d\n", cache_size);
+	ddjvu_cache_set_size(doc->context, (unsigned long)cache_size);
+
 	doc->doc_ref = ddjvu_document_create_by_filename_utf8(doc->context, filename, TRUE);
 	while (! ddjvu_document_decoding_done(doc->doc_ref))
 		handle(L, doc->context, True);
@@ -447,6 +450,21 @@ static int drawPage(lua_State *L) {
 	return 0;
 }
 
+static int getCacheSize(lua_State *L) {
+	DjvuDocument *doc = (DjvuDocument*) luaL_checkudata(L, 1, "djvudocument");
+	unsigned long size = ddjvu_cache_get_size(doc->context);
+	printf("## ddjvu_cache_get_size = %d\n", size);
+	lua_pushnumber(L, size);
+	return 1;
+}
+
+static int cleanCache(lua_State *L) {
+	DjvuDocument *doc = (DjvuDocument*) luaL_checkudata(L, 1, "djvudocument");
+	printf("## ddjvu_cache_clear\n");
+	ddjvu_cache_clear(doc->context);
+	return 0;
+}
+
 static const struct luaL_Reg djvu_func[] = {
 	{"openDocument", openDocument},
 	{NULL, NULL}
@@ -458,6 +476,8 @@ static const struct luaL_Reg djvudocument_meth[] = {
 	{"getToc", getTableOfContent},
 	{"getPageText", getPageText},
 	{"close", closeDocument},
+	{"getCacheSize", getCacheSize},
+	{"cleanCache", cleanCache},
 	{"__gc", closeDocument},
 	{NULL, NULL}
 };
diff --git a/djvureader.lua b/djvureader.lua
index cd0ad9885..be72ec4c0 100644
--- a/djvureader.lua
+++ b/djvureader.lua
@@ -6,7 +6,7 @@ DJVUReader = UniReader:new{}
 -- DJVU does not support password yet
 function DJVUReader:open(filename)
 	local ok
-	ok, self.doc = pcall(djvu.openDocument, filename)
+	ok, self.doc = pcall(djvu.openDocument, filename, self.cache_document_size)
 	if not ok then
 		return ok, self.doc -- this will be the error message instead
 	end
diff --git a/einkfb.c b/einkfb.c
index a1f7054f9..cfc268719 100644
--- a/einkfb.c
+++ b/einkfb.c
@@ -150,6 +150,16 @@ static int einkUpdate(lua_State *L) {
 	ioctl(fb->fd, FBIO_EINK_UPDATE_DISPLAY_AREA, &myarea);
 #else
 	// for now, we only do fullscreen blits in emulation mode
+	if (fxtype == 0) {
+		// simmulate a full screen update in eink screen
+		if(SDL_MUSTLOCK(fb->screen) && (SDL_LockSurface(fb->screen) < 0)) {
+			return luaL_error(L, "can't lock surface.");
+		}
+		SDL_FillRect(fb->screen, NULL, 0x000000);
+		if(SDL_MUSTLOCK(fb->screen)) SDL_UnlockSurface(fb->screen);
+		SDL_Flip(fb->screen);
+	}
+
 	if(SDL_MUSTLOCK(fb->screen) && (SDL_LockSurface(fb->screen) < 0)) {
 		return luaL_error(L, "can't lock surface.");
 	}
diff --git a/pdf.c b/pdf.c
index e99d17430..87190f14d 100644
--- a/pdf.c
+++ b/pdf.c
@@ -164,16 +164,16 @@ fz_alloc_context my_alloc_default =
 
 static int openDocument(lua_State *L) {
 	char *filename = strdup(luaL_checkstring(L, 1));
-	int cachesize = luaL_optint(L, 2, 64 << 20); // 64 MB limit default
+	int cache_size = luaL_optint(L, 2, 64 << 20); // 64 MB limit default
 	char buf[15];
-	printf("cachesize: %s\n",readable_fs(cachesize,buf));
+	printf("## cache_size: %s\n",readable_fs(cache_size,buf));
 
 	PdfDocument *doc = (PdfDocument*) lua_newuserdata(L, sizeof(PdfDocument));
 
 	luaL_getmetatable(L, "pdfdocument");
 	lua_setmetatable(L, -2);
 
-	doc->context = fz_new_context(&my_alloc_default, NULL, cachesize);
+	doc->context = fz_new_context(&my_alloc_default, NULL, cache_size);
 
 	fz_try(doc->context) {
 		doc->xref = fz_open_document(doc->context, filename);
@@ -424,6 +424,17 @@ static int drawPage(lua_State *L) {
 	return 0;
 }
 
+static int getCacheSize(lua_State *L) {
+	printf("## mupdf getCacheSize = %d\n", msize);
+	lua_pushnumber(L, msize);
+	return 1;
+}
+
+static int cleanCache(lua_State *L) {
+	printf("## mupdf cleanCache NOP\n");
+	return 0;
+}
+
 static const struct luaL_Reg pdf_func[] = {
 	{"openDocument", openDocument},
 	{NULL, NULL}
@@ -436,6 +447,8 @@ static const struct luaL_Reg pdfdocument_meth[] = {
 	{"getPages", getNumberOfPages},
 	{"getToc", getTableOfContent},
 	{"close", closeDocument},
+	{"getCacheSize", getCacheSize},
+	{"cleanCache", cleanCache},
 	{"__gc", closeDocument},
 	{NULL, NULL}
 };
diff --git a/pdfreader.lua b/pdfreader.lua
index ec4e1a105..9413e0127 100644
--- a/pdfreader.lua
+++ b/pdfreader.lua
@@ -8,7 +8,7 @@ function PDFReader:open(filename)
 	-- muPDF manages its own cache, set second parameter
 	-- to the maximum size you want it to grow
 	local ok
-	ok, self.doc = pcall(pdf.openDocument, filename, 64*1024*1024)
+	ok, self.doc = pcall(pdf.openDocument, filename, self.cache_document_size)
 	if not ok then
 		return false, self.doc -- will contain error message
 	end
diff --git a/unireader.lua b/unireader.lua
index a45776042..884b2d7c7 100644
--- a/unireader.lua
+++ b/unireader.lua
@@ -67,11 +67,12 @@ UniReader = {
 
 	-- 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 = {},
+	-- renderer cache size
+	cache_document_size = 1024*1024*8, -- FIXME random, needs testing
 
 	pagehash = nil,
 
@@ -107,7 +108,7 @@ end
 
 -- open a file and its settings store
 -- tips: you can use self:loadSettings in open() method.
-function UniReader:open(filename, password)
+function UniReader:open(filename, cache_size)
 	return false
 end
 
@@ -128,6 +129,18 @@ function UniReader:toggleTextHighLight(word_list)
 	return
 end
 
+----------------------------------------------------
+-- renderer memory
+----------------------------------------------------
+
+function UniReader:getCacheSize()
+	return -1
+end
+
+function UniReader:cleanCache()
+	return
+end
+
 
 --[ following are default methods ]--
 function UniReader:initGlobalSettings(settings)
@@ -145,11 +158,16 @@ function UniReader:initGlobalSettings(settings)
 	if cache_max_ttl then
 		self.cache_max_ttl = cache_max_ttl
 	end
+
+	local rcountmax = settings:readSetting("partial_refresh_count")
+	if rcountmax then
+		self.rcountmax = rcountmax
+	end
 end
 
 function UniReader:loadSettings(filename)
 	if self.doc ~= nil then
-		self.settings = DocSettings:open(filename)
+		self.settings = DocSettings:open(filename,self.cache_document_size)
 
 		local gamma = self.settings:readSetting("gamma")
 		if gamma then
@@ -198,6 +216,7 @@ function UniReader:cacheClaim(size)
 			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].bb:free()
 				self.cache[k] = nil
 			end
 		end
@@ -516,7 +535,7 @@ function UniReader:show(no)
 		self:toggleTextHighLight(self.highlight[no])
 	end
 
-	if self.rcount == self.rcountmax then
+	if self.rcount >= self.rcountmax then
 		print("full refresh")
 		self.rcount = 1
 		fb:refresh(0)
@@ -800,11 +819,20 @@ end
 function UniReader:_drawReadingInfo()
 	local ypos = height - 50
 	local load_percent = (self.pageno / self.doc:getPages())
-
-	fb.bb:paintRect(0, ypos, width, 50, 0)
-
-	ypos = ypos + 15
 	local face, fhash = Font:getFaceAndHash(22)
+
+	-- display memory on top of page
+	fb.bb:paintRect(0, 0, width, 15+6*2, 0)
+	renderUtf8Text(fb.bb, 10, 15+6, face, fhash,
+		"Memory: "..
+		math.ceil( self.cache_current_memsize / 1024 ).."/"..math.ceil( self.cache_max_memsize / 1024 )..
+		" "..math.ceil( self.doc:getCacheSize() / 1024 ).."/"..math.ceil( self.cache_document_size / 1024 ).." k",
+	true)
+
+	-- display reading progress on bottom of page
+	local ypos = height - 50
+	fb.bb:paintRect(0, ypos, width, 50, 0)
+	ypos = ypos + 15
 	local cur_section = self:getTocTitleByPage(self.pageno)
 	if cur_section ~= "" then
 		cur_section = "Section: "..cur_section
@@ -828,6 +856,8 @@ function UniReader:showMenu()
 		if ev.type == EV_KEY and ev.value == EVENT_VALUE_KEY_PRESS then
 			if ev.code == KEY_BACK or ev.code == KEY_MENU then
 				return
+			elseif ev.code == KEY_C then
+				self.doc:cleanCache()
 			end
 		end
 	end
@@ -1061,6 +1091,12 @@ function UniReader:addAllCommands()
 			unireader:showHighLight()
 			unireader:goto(unireader.pageno)
 		end)
+	self.commands:add(KEY_R, MOD_SHIFT, "R",
+		"manual full screen refresh",
+		function(unireader)
+			unireader.rcount = 1
+			fb:refresh(0)
+		end)
 	self.commands:add(KEY_HOME,nil,"Home",
 		"exit application",
 		function(unireader)