thinkpad-ec/docs/table_matrix.txt

The basic design of the thinkpad keyboard is one of a 16 column matrix
with 8 rows.  While this layout is not specifically related to the
physical layout of the actual keys, some of it is dictated by that layout.

The mapping of logical-row+column into a EC scancode is done with a
table in the EC firmware.  This table is largely the same between all
the models investigated and served as the basis of the classic keyboard
modification.



ThinkPad x220 matrix:
---------------------

This table is arranged in a array of bytes that is 16 columns by 17 rows,
with the second half of each row being unused (except for one anomaly)

This corresponds to the physical hardware, which uses 16 "drive" lines
and 8 "sense" lines - with one extra row, probably for some software keys.

The hardware "drive" line forms the row number and the "sense" line forms
the column number.

             0  1  2  3  4  5  6  7    0    1    2    3    4    5    6    7

matrix[ 0]: 01 02 11 10 1f 6e 2e 83   `    1    Q    TAB  A    Esc  Z    ??
matrix[ 1]: 70 03 12 1e 20 2d 2f 00   F1   2    W    CpLk S    (|)  X
matrix[ 2]: 71 04 13 72 21 73 30 00   F2   3    E    F3   D    F4   C
matrix[ 3]: 06 05 14 15 22 23 31 32   5    4    R    T    F    G    V    B
matrix[ 4]: 07 08 17 16 25 24 34 33   6    7    U    Y    J    H    M    N
matrix[ 5]: 0d 09 18 1c 26 75 35 38   =    8    I    ]    K    F6   ,    (/)
matrix[ 6]: 77 0a 19 76 27 84 36 85   F8   9    O    F7   L    ??   .    ??
matrix[ 7]: 0c 0b 1a 1b 28 29 2a 37   -    0    P    [    ;    '    (#)  ?
matrix[ 8]: 78 79 0e 0f 1d 74 2b 3d   F9   F10  ??   BS   \    F5   Ent  Spc
matrix[ 9]: 4b 7b 00 9b 00 00 00 59   Ins  F12       WinL                Rgt
matrix[10]: 4c 7a 9a 99 98 97 a0 54   Del  F11  Vol+ Vol- Mute IBM  Mic  Down
matrix[11]: 55 56 00 00 9c 00 89 8a   PgUp PgDn           Menu      PgBk PgFd
matrix[12]: 50 51 00 00 00 53 7e 4f   Home End                 Up   Paus Left
matrix[13]: 00 7c 7d 00 00 3c 00 3e        PrSc ScLk           AltL      AltR
matrix[14]: 00 00 00 2c 00 00 39 00                  SftL           SftR     
matrix[15]: 3a 00 00 00 00 00 40 00   CtlL                          CtlR
 
matrix[15][15] = 0x96                 ??
matrix[16]: 00 9d 00 9e 9f 4a 3a 00        WinR?     Pwr? Slp? Wak? CtlL

Unknown key codes: 0x0e 0x83 0x84 0x85 0x96

    (source: x220 EC firmware version 8DHT34WW, offset 0x1f080)

ThinkPad x230 matrix:
---------------------

The x230 uses the same basic table layout as the x220 and shares its
contents with all of the xx30 series laptops.  The basic classic keyboard
fix was made by updating the x230 table to look like the x220, combined
with updating the live/dead key table.

             0  1  2  3  4  5  6  7    0    1    2    3    4    5    6    7

matrix[ 0]: 01 02 11 10 1f 6e 2e 83   `    1    Q    TAB  A    Esc  Z    ??
matrix[ 1]: 70 03 12 1e 20 2d 2f 00   F1   2    W    CpLk S    (|)  X
matrix[ 2]: 71 04 13 72 21 73 30 00   F2   3    E    F3   D    F4   C
matrix[ 3]: 06 05 14 15 22 23 31 32   5    4    R    T    F    G    V    B
matrix[ 4]: 07 08 17 16 25 24 34 33   6    7    U    Y    J    H    M    N
matrix[ 5]: 0d 09 18 1c 26 75 35 38   =    8    I    ]    K    F6   ,    (/)
matrix[ 6]: 77 0a 19 76 27 84 36 85   F8   9    O    F7   L    ??   .    ??
matrix[ 7]: 0c 0b 1a 1b 28 29 2a 37   -    0    P    [    ;    '    (#)  ?
matrix[ 8]: 78 79 0e 0f 1d 74 2b 3d   F9   F10  ??   BS   \    F5   Ent  Spc
matrix[ 9]: 00 7b 00 9b 00 00 00 59        F12       WinL                Rgt
matrix[10]: 50 7a 9a 99 98 97 a0 54   Home F11  Vol+ Vol- Mute IBM  Mic  Down
matrix[11]: 4c 4b 00 00 7c 00 55 56   Del  Ins            PrSc      PgUp PgDn
matrix[12]: 00 51 00 00 00 53 00 4f        End                 Up        Left
matrix[13]: 00 00 00 00 00 3c 00 3e                            AltL      AltR
matrix[14]: 00 00 00 2c 00 00 39 00                  SftL           SftR
matrix[15]: 3a 00 00 00 00 00 40 00   CtlL                          CtlR

matrix[15][15] = 0x96                 ??
matrix[16]:   00 9d 00 9e 9f 4a 3a 9c      WinR?     Pwr? Slp? Wak? CtlL Menu
matrix[16][8] 7d 7e 00 00 00 00 00 00 ScLk Paus

Unknown key codes: 0x0e 0x83 0x84 0x85 0x96

    (source: x230 EC firmware version G2HT35WW, offset 0x218d8)

ThinkPad x230 live/dead bitmap:
-------------------------------

Again, this table is shared with all of the xx30 series laptops.  There is
a similar table in the x220 EC firmware, but with a different endianess (as
a result of the different embedded controller used in the x220)

The live/dead bitmap is an array of 16 words, each word being 16 bits long.
Each detected keypress is looked up in this array - the "drive" line is used
as the index into the array and the "sense" line is the bit number in that
word.  If the bit at that location is set, then the keypress is considered
a "live" key and the value from the matrix table is used as the embedded
controller scancode of the key pressed (Note that this scancode is internal
to the EC - it is not the same as the BIOS scancode)

    (source: x230 EC firmware version G2HT35WW, offset 0x219e8)