Panasonic VP-0187A
==================
It is unknown keyboard from Panasonic
6P6C connector
Hirose Cheery M8 switches
https://deskthority.net/wiki/Cherry_M8
Scan
----
The keyboard is comprised of some of 4000 series IC without microcontroller.
RST>-----------+---------------+
| |
TC4520 | TC4520 |
--------- carry ---------
CLK>--->|row |------>|col |
|counter|Q3 |counter|
--------- ---------
Q012 Q012
||| |||
||| ABC TC4028
||| ---------
||| |decoder|
||| ---------
||| |||||| col[0..7]
ABC vvvvvvv pull down
---------- <----|+++++++|--100K--+
|data | <----|+++++++|--100K--+
STATE<--|selector| <----|+++++++|--100K--+
| 7 to 1 | <----|+++++++|--100K--+
---------- <----|+++++++|--100K--+
row[0..7] |
8x8 matrix -
GND
Matrix
------
0 1 2 3 4 5 6 7
--------------------------------------------------------------------
0 ESC 1 2 3 4 5 6 7
1 8 9 0 - ^ BS INS DEL
2 TAB Q W E R T Y U
3 I O P @ [ ] F2 F1
4 CTRL A S D F G H J
5 K L ; : RETURN UP F3 F4
6 SHIFT Z X C V B N M
7 SPACE , . / LEFT RIGHT DOWN HOME
6P6C connector pinout
---------------------
1. VCC
2. Clock - sends clock to binary counter TC4520
3. Key State - indicates hi if key selected by counter is active
4. Sense - indicates hi if any key is active while Reset is hi.
5. Reset - resets counter and drives all column
6. GND
123456
,--------.
| |
| |
`--____--'
plug
