Add connector pinouts

converter/ibm4704_usb/4704.txt

@@ -16,7 +16,6 @@ http://ed-thelen.org/comp-hist/IBM-ProdAnn/4700.pdf
 
 
 
-
 4704 Keyboard Protocol
 ======================
 On powering up the keyboard sends keyboard id; A3h for 6019284(62-key), for example.
@@ -24,6 +23,22 @@ After that firmware enters FC command mode and waits for parameter data from hos
 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.
@@ -40,7 +55,6 @@ Timing:     Host reads bit while Clock is hi.
 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.
@@ -60,7 +74,6 @@ Timing:     After Request keyboard pull up Data and down Clock line to low for s
 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.