modified: overview.md

	modified:   part1/simple_detector.md

src/docs/overview.md

@@ -3,20 +3,28 @@ title: "Overview"
 ---
 
 
-## Data model
+## EIC Data model
 
-
-## PODIO  
+### PODIO  
 
 - Eicweb fork: https://eicweb.phy.anl.gov/EIC/podio
 - AIDAsoft repo: https://github.com/AIDASoft/podio
 
-## LCIO2 
+### LCIO2 
 
 [Defined in yaml 
 file](https://eicweb.phy.anl.gov/EIC/podio/blob/master/lcio2/lcio-edm.yaml) 
 which is used to generate C++ library.
 
-![data model use](data_model_use.png)
+![data model use](data_model_use2.png)
 
 ![data model layer](data_model_layers.png)
+
+
+## NPDet - Nuclear physics detector library
+
+As we will learn the compact detector description files are used to build detectors from a parameterized detector library. 
+NPDet is a collection of _generic detectors_ and _concept detectors_. 
+
+In a hack-a-thon we will add to this detector library.
+

src/docs/part1/simple_detector.md

@@ -50,13 +50,14 @@ ddsim  --runType run  --enableG4GPS \
    --outputFile gem_tracker_sim.root 
 ```
 
-## 
-Supports multiple languages.
 
-The following is a code block with diff. Lines with `+` highlighted in green shade indicating an addition. Lines with `-` highlighted in red shade indicating a deletion.
+This will run geant4 using the General Particle Source (GPS) tool.
+The output will be a root file containing the generated events and GEM tracker hits.
 
-```javascript
-- const data = ['1','2'];
-+ const data = [1,2];
+## Digitization 
+
+```bash
+root -b -q example_digi.cxx+
 ```
+![digi histogram](example_digi.png)