1 files changed, 17 insertions, 0 deletions
diff --git a/doc/internal/scantabs.txt b/doc/internal/scantabs.txt
new file mode 100644
index 0000000..208da08
--- /dev/null
+++ b/doc/internal/scantabs.txt
@@ -0,0 +1,17 @@
+scan table file header:
+  uint32_t: number of scan tables
+  0x10 aligned scan table records
+
+scan table record:
+  uint32_t offset in file of table data / 0x200
+  uint8_t: length of prefix
+  uint8_t's: prefix
+
+table data (0x200 aligned):
+  first key down table then key up table
+  uint8_t's:
+    0x00: bad scancode
+    0x01: prefix (go to table)
+    0x02: wrong polarity (go to other up or down)
+    0x03: good scancode, no keycode
+    other: keycode