135 lines
3.8 KiB
Plaintext
135 lines
3.8 KiB
Plaintext
|
ADB Protocol
|
||
|
|
============
|
||
|
|
|
||
|
|
Resources
|
||
|
|
---------
|
||
|
|
Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)]
|
||
|
|
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
|
||
|
|
ADB Keycode
|
||
|
|
http://72.0.193.250/Documentation/macppc/adbkeycodes/
|
||
|
|
http://m0115.web.fc2.com/m0115.jpg
|
||
|
|
ADB Signaling
|
||
|
|
http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
|
||
|
|
ADB Overview & History
|
||
|
|
http://en.wikipedia.org/wiki/Apple_Desktop_Bus
|
||
|
|
Microchip Application Note: ADB device(with code for PIC16C)
|
||
|
|
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
|
||
|
|
AVR ATtiny2131 ADB to PS/2 converter(Japanese)
|
||
|
|
http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
|
||
|
|
|
||
|
|
|
||
|
|
Pinouts
|
||
|
|
-------
|
||
|
|
Female socket from the front
|
||
|
|
|
||
|
|
4o o3
|
||
|
|
2o o1
|
||
|
|
==
|
||
|
|
|
||
|
|
1: Data
|
||
|
|
2: Power SW(low when press Power key)
|
||
|
|
3: Vcc(5V)
|
||
|
|
4: GND
|
||
|
|
|
||
|
|
|
||
|
|
Commands
|
||
|
|
--------
|
||
|
|
ADB command is 1byte and consists of 4bit-address, 2bit-command
|
||
|
|
type and 2bit-register. The commands are always sent by Host.
|
||
|
|
|
||
|
|
Command format:
|
||
|
|
7 6 5 4 3 2 1 0
|
||
|
|
| | | |------------ address
|
||
|
|
| |-------- command type
|
||
|
|
| |---- register
|
||
|
|
|
||
|
|
bits commands
|
||
|
|
------------------------------------------------------
|
||
|
|
- - - - 0 0 0 0 Send Request(reset all devices)
|
||
|
|
A A A A 0 0 0 1 Flush(reset a device)
|
||
|
|
- - - - 0 0 1 0 Reserved
|
||
|
|
- - - - 0 0 1 1 Reserved
|
||
|
|
- - - - 0 1 - - Reserved
|
||
|
|
A A A A 1 0 R R Listen(write to a device)
|
||
|
|
A A A A 1 1 R R Talk(read from a device)
|
||
|
|
|
||
|
|
The command to read keycodes from keyboard is 0x2C which
|
||
|
|
consist of keyboard address 2 and Talk against register 0.
|
||
|
|
|
||
|
|
Address:
|
||
|
|
2: keyboard
|
||
|
|
3: mice
|
||
|
|
|
||
|
|
Registers:
|
||
|
|
0: application(keyobard/mice use to store its data.)
|
||
|
|
1: application
|
||
|
|
2: application
|
||
|
|
3: status and command
|
||
|
|
|
||
|
|
|
||
|
|
Communication
|
||
|
|
-------------
|
||
|
|
This is a minimum information for keyboard communication.
|
||
|
|
See "Resources" for detail.
|
||
|
|
|
||
|
|
Signaling:
|
||
|
|
|
||
|
|
~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
|
||
|
|
|
||
|
|
|800us | |7 Command 0| | | |15-64 Data 0|Stopbit(0)
|
||
|
|
+Attention | | | +Startbit(1)
|
||
|
|
+Startbit(1) | +Tlt(140-260us)
|
||
|
|
+stopbit(0)
|
||
|
|
|
||
|
|
Bit cells:
|
||
|
|
|
||
|
|
bit0: ______~~~
|
||
|
|
65 :35us
|
||
|
|
|
||
|
|
bit1: ___~~~~~~
|
||
|
|
35 :65us
|
||
|
|
|
||
|
|
bit0 low time: 60-70% of bit cell(42-91us)
|
||
|
|
bit1 low time: 30-40% of bit cell(21-52us)
|
||
|
|
bit cell time: 70-130us
|
||
|
|
[from Apple IIgs Hardware Reference Second Edition]
|
||
|
|
|
||
|
|
Criterion for bit0/1:
|
||
|
|
After 55us if line is low/high then bit is 0/1.
|
||
|
|
|
||
|
|
Attention & start bit:
|
||
|
|
Host asserts low in 560-1040us then places start bit(1).
|
||
|
|
|
||
|
|
Tlt(Stop to Start):
|
||
|
|
Bus stays high in 140-260us then device places start bit(1).
|
||
|
|
|
||
|
|
Global reset:
|
||
|
|
Host asserts low in 2.8-5.2ms. All devices are forced to reset.
|
||
|
|
|
||
|
|
Send request from device(Srq):
|
||
|
|
Device can request to send at commad(Global only?) stop bit.
|
||
|
|
keep low for 300us to request.
|
||
|
|
|
||
|
|
|
||
|
|
Keyboard data(register0)
|
||
|
|
This 16bit data can contains 2 keycodes and 2 released flags.
|
||
|
|
First keycode is palced in upper nibble. When one keyocode is sent,
|
||
|
|
lower nibble is 0xFF.
|
||
|
|
Release flag is 1 when key is released.
|
||
|
|
|
||
|
|
15 14 . . . . . 8 7 6 . . . . . 0
|
||
|
|
| |keycode1 | |keycode2
|
||
|
|
|released(1) |released(1)
|
||
|
|
|
||
|
|
Keycodes:
|
||
|
|
Scancode consists of 7bit keycode and 1bit release flag.
|
||
|
|
Device can send two keycodes at once. If just one keycode is sent
|
||
|
|
keycode1 contains it and keyocode2 is 0xFF.
|
||
|
|
|
||
|
|
Power switch:
|
||
|
|
You can read the state from PSW line(active low) however
|
||
|
|
the switch has a special scancode 0x7F7F, so you can
|
||
|
|
also read from Data line. It uses 0xFFFF for release scancode.
|
||
|
|
|
||
|
|
END_OF_ADB
|