OK, so here's the info I gathered about my Red Scarf II. If you need some photos, just ask.
Board Info
==========
- Silkscreen on the bottom side says "Red Scarf II 60" and "Ver.A". Top side "logo" says "RS60".
- This version has no ISO option, only ANSI.
- Right shift can be split, backspace can be split (HHKB-style).
- DFU bootloader (activated on reset, does not erase eeprom on erase).
- AVR ISP pins are broken out to through-hole pads (yay!), order is (starting from the end closer to the middle of the board).
gnd miso vcc sck mosi reset
- The [TMK files from Kai Ryu](https://github.com/kairyu/tmk_keyboard_custom/blob/master/keyboard/RedScarfII) work with this keyboard. Note that these sources assume a bigger keyboard (numpad + function keys), but 60% is really just a subset of that.
Summary
=======
Rows
----
Row selection is done via a 74HCT138 decoder. Its inputs are routed to PB0, PB1 and PB2. Rows are unselected by taking these high. Rows (0,1,2,3,4 for the 60% version) are selected by writing the binary representation of the row to the three pins; here's a table from the above sources:
row: 0 1 2 3 4 5 x
pin: B2 0 1 0 1 0 1 1
B1 0 0 1 1 0 0 1
B0 0 0 0 0 1 1 1
Initialisation is just marking the pins as outputs.
Columns
-------
Tied like this:
col: 0 1 2 3 4 5 6 7 8 9 10 11 12 13
pin: F4 F1 F0 B3 D0 D1 D4 D5 D6 D7 F7 F6 D2 D3
-------------------------------------------------------------
|C0 | C1| C2| C3| C4| C5| C6| C7| C8| C9|C10|C11|C12| C13 |(R2,C12 if split Bsp)
+-----------------------------------------------------------+
|C0 | C1| C2| C3| C4| C5| C6| C7| C8| C9|C10|C11|C12| C13 |
+-----------------------------------------------------------+
|C0 | C1| C2| C3| C4| C5| C6| C7| C8| C9|C10|C11| C13 |
+-----------------------------------------------------------+
|C0 | C2| C3| C4| C5| C6| C7| C8| C9|C10|C11| C12 |C13|
+-----------------------------------------------------------+
|C0 | C1 | C2 | C9 |C10 |C11 |C12 |C13 |
-------------------------------------------------------------
Initialised as inputs with pull-ups; triggered when low.
Wiring
------
Column_pin --- switch --- diode anode (+) --- diode cathode (-) --- row pin on 74HCT138
LEDs
----
- CapsLock: PC7 (on when pin low)
- Logo: PC6 (this is 4 SMT leds on the bottom side below spacebar + one unpopulated SMT led on the bottom side, edge below Tab) (on when pin high)
- Backlight: PB7 (on when pin high)
- There is no numlock LED.
I would be really happy if you could add support for this board into your firmware! (I'm willing to test!)