The ti89's keyboard matrix :

Row     +-------+-------+-------+-------+-------+-------+-------+-------+
 V  Col>| Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| Bit 0 | alpha |diamond| shift |  2nd  | right | down  | left  |  up   |
| Bit 1 |  F5   | clear |   ^   |   /   |   *   |   -   |   +   | ENTER |
| Bit 2 |  F4   |backspc|   T   |   ,   |   9   |   6   |   3   |  (-)  |
| Bit 3 |  F3   |catalog|   Z   |   )   |   8   |   5   |   2   |   .   |
| Bit 4 |  F2   | mode  |   Y   |   (   |   7   |   4   |   1   |   0   |
| Bit 5 |  F1   | home  |   X   |   =   |   |   |  EE   |  STO  | APPS  |
| Bit 6 |       |       |       |       |       |       |       |  ESC  |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+

The ti92's keyboard matrix :

Row     +-------+-------+-------+-------+-------+-------+-------+-------+
 V  Col>| Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| Bit 0 |  down | right |   up  |  left |  hand | shift |diamond|  2nd  |
| Bit 1 |   3   |   2   |   1   |   F8  |   W   |   S   |   Z   | unused|
| Bit 2 |   6   |   5   |   4   |   F3  |   E   |   D   |   X   | unused|
| Bit 3 |   9   |   8   |   7   |   F7  |   R   |   F   |   C   |  STO  |
| Bit 4 |   ,   |   )   |   (   |   F2  |   T   |   G   |   V   | space |
| Bit 5 |  TAN  |  COS  |  SIN  |   F6  |   Y   |   H   |   B   |   /   |
| Bit 6 |   P   | ENTER2|   LN  |   F1  |   U   |   J   |   N   |   ^   |
| Bit 7 |   *   |  APPS | CLEAR |   F5  |   I   |   K   |   M   |   =   |
| Bit 8 | unused|  ESC  |  MODE |   +   |   O   |   L   | theta |backspc|
| Bit 9 |  (-)  |   .   |   0   |   F4  |   Q   |   A   | ENTER1|   -   |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+

See lowlevel.doc in fargoII package for the usage of these matrix.
Th.FERNIQUE <FFernique@eisti.fr>
17/10/98.