diff --git a/README.md b/README.md
index 78a8deed7e86f8ff0fd541dc3cc29358a306e20b..fdc73927980ac34005dd6c51f1e42bf1a1b466ed 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,9 @@
 # Moberg
 
 A library for connecting to various input/output libraries
-with a common (very simple interface).
+with a common interface. The C api is:
 
-```C
+```c
 struct moberg_t;
 struct moberg_digital_in_t;
 
@@ -14,4 +14,22 @@ struct moberg_digital_in_t *moberg_open_digital_in(
   const struct moberg_t *handle,
   int channel);
   
+```
+
+Config files are formatted as
+
+```
+comedi = {
+    device = /dev/comedi0
+    modprobe = [ comedi 8255 comedi_fc mite ni_tio ni_tiocmd ni_pcimio ]
+    config = [ ni_pcimio ]
+    # Moberg mapping[indices] = driver specific[indices]
+    map digital_in[0:7] = subdevice[4][0:7]
+}
+serial2002 = {
+    device = /dev/ttyS0
+    baud = 115200
+    # Moberg mapping[indices] = driver specific[indices]
+    map digital_in[30:37] = digital_in[0:7]
+}
 ```
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