+
+
+
+/*
+Primitive M0110 Library for AVR
+==============================
+
+
+Signaling
+---------
+CLOCK is always from KEYBOARD. DATA are sent with MSB first.
+
+1) IDLE: both lines are high.
+ CLOCK ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ DATA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+2) KEYBOARD->HOST: HOST reads bit on rising edge.
+ CLOCK ~~~~~~~~~~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~~~~~~~~~
+ DATA ~~~~~~~~~~~~X777777X666666X555555X444444X333333X222222X111111X000000X~~~~~~~
+ <--> 160us(clock low)
+ <---> 180us(clock high)
+
+3) HOST->KEYBOARD: HOST asserts bit on falling edge.
+ CLOCK ~~~~~~~~~~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~|__|~~~~~~~~~~~
+ DATA ~~~~~~|_____X777777X666666X555555X444444X333333X222222X111111X000000X~~~~~~~
+ <----> 840us(request to send by host) <---> 80us(hold DATA)
+ <--> 180us(clock low)
+ <---> 220us(clock high)
+
+
+Protocol
+--------
+COMMAND:
+ Inquiry 0x10 get key event with block
+ Instant 0x12 get key event
+ Model 0x14 get model number(M0110 responds with 0x09)
+ bit 7 1 if another device connected(used when keypad exists?)
+ bit4-6 next device model number
+ bit1-3 keyboard model number
+ bit 0 always 1
+ Test 0x16 test(ACK:0x7D/NAK:0x77)
+
+KEY EVENT:
+ bit 7 key state(0:press 1:release)
+ bit 6-1 scan code(see below)
+ bit 0 always 1
+ To get scan code use this: ((bits&(1<<7)) | ((bits&0x7F))>>1).
+
+ Note: On the M0110A, Keypad keys and Arrow keys are preceded by 0x79.
+ Moreover, some Keypad keys(=, /, * and +) are preceded by 0x71 on press and 0xF1 on release.
+
+ARROW KEYS:
+ Arrow keys and Calc keys(+,*,/,= on keypad) share same byte sequence and preceding byte of
+ Calc keys(0x71 and 0xF1) means press and release event of SHIFT. This causes a very confusing situation,
+ it is difficult or impossible to tell Calc key from Arrow key plus SHIFT in some cases.
+
+ Raw key events:
+ press release
+ ---------------- ----------------
+ Left: 0x79, 0x0D 0x79, 0x8D
+ Right: 0x79, 0x05 0x79, 0x85
+ Up: 0x79, 0x1B 0x79, 0x9B
+ Down: 0x79, 0x11 0x79, 0x91
+ Pad+: 0x71, 0x79, 0x0D 0xF1, 0x79, 0x8D
+ Pad*: 0x71, 0x79, 0x05 0xF1, 0x79, 0x85
+ Pad/: 0x71, 0x79, 0x1B 0xF1, 0x79, 0x9B
+ Pad=: 0x71, 0x79, 0x11 0xF1, 0x79, 0x91
+
+
+RAW CODE:
+ M0110A
+ ,---------------------------------------------------------. ,---------------.
+ | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Bcksp| |Clr| =| /| *|
+ |---------------------------------------------------------| |---------------|
+ |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -|
+ |-----------------------------------------------------' | |---------------|
+ |CapsLo| A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +|
+ |---------------------------------------------------------| |---------------|
+ |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft|Up | | 1| 2| 3| |
+ |---------------------------------------------------------' |-----------|Ent|
+ |Optio|Mac | Space | \|Lft|Rgt|Dn | | 0| .| |
+ `---------------------------------------------------------' `---------------'
+ ,---------------------------------------------------------. ,---------------.
+ | 65| 25| 27| 29| 2B| 2F| 2D| 35| 39| 33| 3B| 37| 31| 67| |+0F|*11|*1B|*05|
+ |---------------------------------------------------------| |---------------|
+ | 61| 19| 1B| 1D| 1F| 23| 21| 41| 45| 3F| 47| 43| 3D| | |+33|+37|+39|+1D|
+ |-----------------------------------------------------' | |---------------|
+ | 73| 01| 03| 05| 07| 0B| 09| 4D| 51| 4B| 53| 4F| 49| |+2D|+2F|+31|*0D|
+ |---------------------------------------------------------| |---------------|
+ | 71| 0D| 0F| 11| 13| 17| 5B| 5D| 27| 5F| 59| 71|+1B| |+27|+29|+2B| |
+ |---------------------------------------------------------' |-----------|+19|
+ | 75| 6F| 63 | 55|+0D|+05|+11| | +25|+03| |
+ `---------------------------------------------------------' `---------------'
+ + 0x79, 0xDD / 0xF1, 0xUU
+ * 0x71, 0x79,DD / 0xF1, 0x79, 0xUU
+
+
+MODEL NUMBER:
+ M0110: 0x09 00001001 : model number 4 (100)
+ M0110A: 0x0B 00001011 : model number 5 (101)
+ M0110 & M0120: ???
+
+
+Scan Code
+---------
+ m0110_recv_key() function returns following scan codes instead of raw key events.
+ Scan codes are 1 byte long and MSB(bit7) is set when key is released.
+
+ M0110
+ ,---------------------------------------------------------.
+ | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs|
+ |---------------------------------------------------------|
+ |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| \|
+ |---------------------------------------------------------|
+ |CapsLo| A| S| D| F| G| H| J| K| L| ;| '|Return|
+ |---------------------------------------------------------|
+ |Shift | Z| X| C| V| B| N| M| ,| ,| /| |
+ `---------------------------------------------------------'
+ |Opt|Mac | Space |Enter|Opt|
+ `------------------------------------------------'
+ ,---------------------------------------------------------.
+ | 32| 12| 13| 14| 15| 17| 16| 1A| 1C| 19| 1D| 1B| 18| 33|
+ |---------------------------------------------------------|
+ | 30| 0C| 0D| 0E| 0F| 10| 11| 20| 22| 1F| 23| 21| 1E| 2A|
+ |---------------------------------------------------------|
+ | 39| 00| 01| 02| 03| 05| 04| 26| 28| 25| 29| 27| 24|
+ |---------------------------------------------------------|
+ | 38| 06| 07| 08| 09| 0B| 2D| 2E| 2B| 2F| 2C| 38|
+ `---------------------------------------------------------'
+ | 3A| 37| 31 | 34| 3A|
+ `------------------------------------------------'
+
+ M0110A
+ ,---------------------------------------------------------. ,---------------.
+ | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Bcksp| |Clr| =| /| *|
+ |---------------------------------------------------------| |---------------|
+ |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -|
+ |-----------------------------------------------------' | |---------------|
+ |CapsLo| A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +|
+ |---------------------------------------------------------| |---------------|
+ |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft|Up | | 1| 2| 3| |
+ |---------------------------------------------------------' |-----------|Ent|
+ |Optio|Mac | Space | \|Lft|Rgt|Dn | | 0| .| |
+ `---------------------------------------------------------' `---------------'
+ ,---------------------------------------------------------. ,---------------.
+ | 32| 12| 13| 14| 15| 17| 16| 1A| 1C| 19| 1D| 1B| 18| 33| | 47| 68| 6D| 62|
+ |---------------------------------------------------------| |---------------|
+ | 30| 0C| 0D| 0E| 0F| 10| 11| 20| 22| 1F| 23| 21| 1E| | | 59| 5B| 5C| 4E|
+ |-----------------------------------------------------' | |---------------|
+ | 39| 00| 01| 02| 03| 05| 04| 26| 28| 25| 29| 27| 24| | 56| 57| 58| 66|
+ |---------------------------------------------------------| |---------------|
+ | 38| 06| 07| 08| 09| 0B| 2D| 2E| 2B| 2F| 2C| 38| 4D| | 53| 54| 55| |
+ |---------------------------------------------------------' |-----------| 4C|
+ | 3A| 37| 31 | 2A| 46| 42| 48| | 52| 41| |
+ `---------------------------------------------------------' `---------------'
+
+
+References
+----------
+Technical Info for 128K/512K and Plus
+ ftp://ftp.apple.asimov.net/pub/apple_II/documentation/macintosh/Mac%20Hardware%20Info%20-%20Mac%20128K.pdf
+ ftp://ftp.apple.asimov.net/pub/apple_II/documentation/macintosh/Mac%20Hardware%20Info%20-%20Mac%20Plus.pdf
+Protocol:
+ Page 20 of Tech Info for 128K/512K
+ http://www.mac.linux-m68k.org/devel/plushw.php
+Connector:
+ Page 20 of Tech Info for 128K/512K
+ http://www.kbdbabel.org/conn/kbd_connector_macplus.png
+Signaling:
+ http://www.kbdbabel.org/signaling/kbd_signaling_mac.png
+ http://typematic.blog.shinobi.jp/Entry/14/
+Scan Codes:
+ Page 22 of Tech Info for 128K/512K
+ Page 07 of Tech Info for Plus
+ http://m0115.web.fc2.com/m0110.jpg
+ http://m0115.web.fc2.com/m0110a.jpg
+*/