keychron_qmk_firmware/converter/x68k_usb

X68000 to USB keyboard protocol converter
=========================================
SHARP X68000 is a hobby computer released in Japan.(1987-93)
http://en.wikipedia.org/wiki/Sharp_X68000

X68000 keyboard has ALPS linear switches.
- DSETK0016CE01   green linear
- DSETK0023CE03   yellow linear


Hardware
--------
Target MCU is ATMega32u4 but other USB capable AVR will also work.
You can use PJRC Teensy as dev board.
    http://www.pjrc.com/teensy/

Wiring:
    Mini-DIN            Teensy
    -----------------------------------------------------
    pin1   +5V          VCC
    pin2   MOUSE        -
    pin3   RXD          PD2(RXD)
    pin4   TXD          PD3(TXD) NOTE: Not supported yet.
    pin5   READY        -
    pin6   REMOTE       -
    pin7   GND          GND


Firmware
--------
Build:
    $ cd x68k_usb
    $ make

And load the binary to MCU with your favorite programmer.
If you use Teensy you can load with PJRC Teensy Loader tool.
    http://www.pjrc.com/teensy/loader.html


*   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *


X68000 Keyboard Protocol
========================
http://kyoutan.jpn.org/uts/pc/pic/x68key/


Connector
---------
Mini DIN 7pin(female connector on computer side)
       7 6 5
       o o o
    4 o  =  o 3
        o o
        2 1

    Mini-DIN
    -------------
    pin1   +5V
    pin2   MOUSE
    pin3   RXD
    pin4   TXD
    pin5   READY
    pin6   REMOTE
    pin7   GND


Signaling
---------
- TXD,RXD
    Asynchronous, 2400baud, 1-startbit(L), 8-databit, 1-stopbit(H)

- READY
    ready/not ready(1/0)


Data from keyboard
------------------
bit 7       make/break flag(0/1)
bit 6-0     following scan code


Data from computer
------------------
- LED contorol ON/OFF(0/1)
    bit 7   1(fixed)
    bit 6   全角
    bit 5   ひらがな
    bit 4   INS
    bit 3   CAPS
    bit 2   コード入力
    bit 1   ローマ字
    bit 0   かな

- Repeat delay
    bit 7   0(fixed)
    bit 6   1(fixed)
    bit 5   1(fixed)
    bit 4   0(fixed)
    bit 3-0 delay
    REPEAT_DELAY = 200+delay*100 ms
    default: 500ms
 
-  Repeat time
    bit 7   0(fixed)
    bit 6   1(fixed)
    bit 5   1(fixed)
    bit 4   1(fixed)
    bit 3-0 time
    REPEAT_TIME = 30+time^2*5 ms
    default: 110ms


Scan Codes
----------
,---. ,---.    ,-------------------,    ,-------------------.  ,-----------. ,---------------.
| 61| | 62|    | 63| 64| 65| 66| 67|    | 68| 69| 6A| 6B| 6C|  | 5A| 5B| 5C| | 5D| 52| 53| 54|
`---' `---'    `-------------------'    `-------------------'  `-----------' `---------------'
,-----------------------------------------------------------.  ,-----------. ,---------------.
| 01| 02| 03| 04| 05| 06| 07| 08| 09| 0A| 0B| 0C| 0D| 0E| 0F|  | 36| 5E| 37| | 3F| 40| 41| 42|
|-----------------------------------------------------------|  |------------ |---------------|
|  10 | 11| 12| 13| 14| 15| 16| 17| 18| 19| 1A| 1B| 1C|     |  | 38| 39| 3A| | 43| 44| 45| 46|
|------------------------------------------------------. 1D |  `---=====---' |---------------|
|  71  | 1E| 1F| 20| 21| 2l| 23| 24| 25| 26| 27| 28| 29|    |   ___| 3C|___  | 47| 48| 49| 4A|
|-----------------------------------------------------------|  | 3B|---| 3D| |-----------|---|
|  70    | 2A| 2B| 2C| 2D| 2E| 2F| 30| 31| 32| 33| 34|   70 |  `---| 3E|---' | 4B| 4C| 4D|   |
`-----------------------------------------------------------|  .---=====---. |-----------| 4E|
       | 5F| 55 | 56 |     35     | 57 | 58 | 59 | 60|         |  72 |  73 | | 4F| 50| 51|   |
       `---------------------------------------------'         `-----------' `---------------'