diff options
Diffstat (limited to 'converter/ibm4704_usb')
| -rw-r--r-- | converter/ibm4704_usb/4704.txt | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/converter/ibm4704_usb/4704.txt b/converter/ibm4704_usb/4704.txt index db584970df..c17d172af1 100644 --- a/converter/ibm4704_usb/4704.txt +++ b/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. |