diff --git a/README.md b/README.md
index 3f4f45b..0829b99 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,45 @@ The software lets you use the keyboard to write and edit text files. It's coded
 
 First you need to download and build the **koxtoolchain** on your development computer. This toolchain, once built, will let you build Go programs that can run on the KOBO.
 
-*TODO : Detailed step to build project*
+### Step by step local built
+
+Note: Using WSL (problems with case-sensitivity in memory) or Github Codespace (long built) is a bit tricky. I recommend using a real Ubuntu machine.
+
+1. Clone or download <https://github.com/koreader/koxtoolchain>
+2. install its dependancies: `sudo apt-get install build-essential autoconf automake bison flex gawk libtool libtool-bin libncurses-dev curl file git gperf help2man texinfo unzip wget`
+3. inside the folder run `./gen-tc.sh kobo` this may take more than 2 hours. (instead you could use the [prebuild version](https://github.com/koreader/koxtoolchain/releases) and unzip, untar in your home folder)
+4. run the `source /home/UserName/Downloads/kobowriter-main/refs/x-compile.sh kobo env bare` as recommended at the end of your build
+5. Make sure you have golang-go installed on your linux distro (via apt or snap, ...)
+6. Clone or download <https://github.com/olup/kobowriter> (you can modify event/key.go for other keyboard layout)
+7. inside its main folder, run `make`.
+8. Kobowriter will be in the build folder.
+
+### Step by step Codespace built
+
+[Codespace](https://github.com/features/codespaces) is a Ubunutu environement that you can use for free in any of your repo directly on the github website.
+
+1. Fork <https://github.com/koreader/koxtoolchain> (green button)
+2. In your new fork, start a new codespace in the GitHub Web UI
+3. Once your codespace is runing type in terinal : `cd "$HOME"`
+4. then download the ToolChain prebuild by runnung `wget https://github.com/koreader/koxtoolchain/releases/download/2021.12/kobo.zip`
+5. then: `unzip kobo.zip`
+6. then: `tar -xvzf kobo.tar.gz`
+7. You should have the x-tools listed in the repo now, you can check with `ls`
+8. Open new terminal and add a file name `x-compile.sh` in your main repo (left column)
+9. Open the file and copy paste the content from <https://github.com/koreader/koxtoolchain/blob/master/refs/x-compile.sh> (you can also download that single file and uploaded it to your codespace)
+10. Run: `source x-compile.sh kobo env bare`
+11. Run: `make` (you can modify event/key.go for other keyboard layout before make)
+12. Remove the kobowriter from the .ignore file
+13. push your changes in your repo.
+14. You new kobowriter will be in the build folder of your repo on the github website!
+
+Notes: 
+
+- Note: if [PR](https://github.com/olup/kobowriter/pull/19/commits/cb27c63a494a55f4b287ee2ac03843809a5d734f) has not been accepted or merge, you have to modify the file screener/screen.go with the folowing [lines](https://github.com/olup/kobowriter/blob/cb27c63a494a55f4b287ee2ac03843809a5d734f/screener/screen.go)
+
+- If you have installed XCSoar with the archive tar.gz below, you can swap your custom build kobowriter with the one in the .adds/kobowriter folder. Like this, you can have custom keyboard layout by modifying the event/key.go and build your own kobowriter.
+
+- You can add other app to launch from the XCSoar interface by adding file in the .kobo/XCSoarData/. For example, add a file containing the following line for adding koreader to the tool list in XCSoar
 
 ## How to install
 
diff --git a/screener/screen.go b/screener/screen.go
index 703f9a4..8e91539 100644
--- a/screener/screen.go
+++ b/screener/screen.go
@@ -87,11 +87,6 @@ func printDiff(previous matrix.Matrix, next matrix.Matrix, fb *gofbink.FBInk, fo
 					fb.ClearScreen(&gofbink.FBInkConfig{
 						IsInverted: next[i][j].IsInverted,
 						NoRefresh:  true,
-					}, &gofbink.FBInkRect{
-						Top:    uint16(i * ttSize),
-						Left:   uint16(j * ttWidth),
-						Height: uint16(ttSize),
-						Width:  uint16(ttWidth),
 					})
 
 					fb.PrintOT(string(next[i][j].Content), &gofbink.FBInkOTConfig{
@@ -122,7 +117,7 @@ func printDiff(previous matrix.Matrix, next matrix.Matrix, fb *gofbink.FBInk, fo
 		}
 	}
 
-	fb.Refresh(0, 0, 0, 0, &gofbink.FBInkConfig{})
+	fb.Refresh(0, 0, 0, 0, gofbink.DitherFloydSteingberg ,&gofbink.FBInkConfig{})
 }
 
 func (s *Screen) PrintPng(imgBytes []byte, w int, h int, x int, y int) {
@@ -158,12 +153,12 @@ func (s *Screen) PrintAlert(message string, width int) {
 }
 
 func (s *Screen) Clear() {
-	s.fb.ClearScreen(&gofbink.FBInkConfig{}, &gofbink.FBInkRect{})
+	s.fb.ClearScreen(&gofbink.FBInkConfig{})
 	s.presentMatrix = matrix.FillMatrix(s.presentMatrix, ' ')
 }
 
 func (s *Screen) ClearFlash() {
-	s.fb.ClearScreen(&gofbink.FBInkConfig{IsFlashing: true}, &gofbink.FBInkRect{})
+	s.fb.ClearScreen(&gofbink.FBInkConfig{IsFlashing: true})
 	s.presentMatrix = matrix.FillMatrix(s.presentMatrix, ' ')
 }