-
4704 Keyboard Protocol
======================
On powering up the keyboard sends keyboard id; A3h for 6019284(62-key), for example.
so that it doesn't send any scancode until you send 'FF'(End of FC command).
+Connector
+---------
+ Keyboard Plug from front
+
+ DSUB-9
+ -------------
+ \ N 2 3 4 5 /
+ \ N N N N /
+ ---------
+ 2 GND
+ 3 VCC 5V
+ 4 DATA
+ 5 CLOCK
+ N No connection/No pin.
+
+
Keyboard to Host
----------------
Data bits are LSB first and Pairty is odd. Clock has around 60us high and 30us low part.
Stop bit: Keyboard pulls down Data line to lo after 9th clock.
-
Host to Keyboard
----------------
Data bits are LSB first and Pairty is odd. Clock has around 60us high and 30us low part.
Stop bit: Host releases or pulls up Data line to hi after 9th clock and waits for keybaord pull down the line to lo.
-
Scancodes
---------
Keyboard doesn't send Break code for all keys except for Alt by default.