ADB to USB keyboard converter

8 files changed, 809 insertions, 0 deletions

diff --git a/ADB.txt b/ADB.txt
new file mode 100644
index 0000000000..b98cf67610
--- /dev/null
+++ b/ADB.txt
@@ -0,0 +1,134 @@
+ADB Protocol
+============
+
+Resources
+---------
+Apple IIgs Hardware Reference Second Edition [p80(Chapter6 p121)]
+    ftp://ftp.apple.asimov.net/pub/apple_II/documentation/Apple%20IIgs%20Hardware%20Reference.pdf
+ADB Keycode
+    http://72.0.193.250/Documentation/macppc/adbkeycodes/
+    http://m0115.web.fc2.com/m0115.jpg
+ADB Signaling
+    http://kbdbabel.sourceforge.net/doc/kbd_signaling_pcxt_ps2_adb.pdf
+ADB Overview & History
+    http://en.wikipedia.org/wiki/Apple_Desktop_Bus
+Microchip Application Note: ADB device(with code for PIC16C)
+    http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011062
+AVR ATtiny2131 ADB to PS/2 converter(Japanese)
+    http://hp.vector.co.jp/authors/VA000177/html/KeyBoardA5DEA5CBA5A2II.html
+
+
+Pinouts
+-------
+    Female socket from the front
+
+      4o  o3
+     2o    o1
+        ==
+
+    1: Data
+    2: Power SW(low when press Power key)
+    3: Vcc(5V)
+    4: GND
+
+
+Commands
+--------
+    ADB command is 1byte and consists of 4bit-address, 2bit-command
+    type and 2bit-register. The commands are always sent by Host.
+
+    Command format:
+    7 6 5 4 3 2 1 0
+    | | | |------------ address
+            | |-------- command type
+                | |---- register
+
+    bits                commands
+    ------------------------------------------------------
+    - - - - 0 0 0 0     Send Request(reset all devices)
+    A A A A 0 0 0 1     Flush(reset a device)
+    - - - - 0 0 1 0     Reserved
+    - - - - 0 0 1 1     Reserved
+    - - - - 0 1 - -     Reserved
+    A A A A 1 0 R R     Listen(write to a device)
+    A A A A 1 1 R R     Talk(read from a device)
+
+    The command to read keycodes from keyboard is 0x2C which
+    consist of keyboard address 2 and Talk against register 0. 
+
+    Address:
+    2:  keyboard
+    3:  mice
+
+    Registers:
+    0: application(keyobard/mice use to store its data.)
+    1: application
+    2: application
+    3: status and command
+
+
+Communication
+-------------
+    This is a minimum information for keyboard communication.
+    See "Resources" for detail.
+
+    Signaling:
+
+    ~~~~____________~~||||||||||||__~~~~~_~~|||||||||||||||__~~~~
+
+        |800us     |  |7 Command 0|  |   |  |15-64  Data  0|Stopbit(0)
+        +Attention |              |  |   +Startbit(1)
+                   +Startbit(1)   |  +Tlt(140-260us)
+                                  +stopbit(0)
+
+    Bit cells:
+
+    bit0: ______~~~
+          65    :35us
+
+    bit1: ___~~~~~~
+          35 :65us
+
+    bit0 low time: 60-70% of bit cell(42-91us)
+    bit1 low time: 30-40% of bit cell(21-52us)
+    bit cell time: 70-130us
+    [from Apple IIgs Hardware Reference Second Edition]
+
+    Criterion for bit0/1:
+    After 55us if line is low/high then bit is 0/1.
+
+    Attention & start bit:
+    Host asserts low in 560-1040us then places start bit(1).
+
+    Tlt(Stop to Start):
+    Bus stays high in 140-260us then device places start bit(1).
+
+    Global reset:
+    Host asserts low in 2.8-5.2ms. All devices are forced to reset.
+
+    Send request from device(Srq):
+    Device can request to send at commad(Global only?) stop bit.
+    keep low for 300us to request.
+
+
+Keyboard data(register0)
+    This 16bit data can contains 2 keycodes and 2 released flags.
+    First keycode is palced in upper nibble. When one keyocode is sent,
+    lower nibble is 0xFF.
+    Release flag is 1 when key is released.
+
+    15 14 . . . . . 8 7 6 . . . . . 0
+    |  |keycode1      | |keycode2
+    |released(1)      |released(1)
+
+    Keycodes:
+    Scancode consists of 7bit keycode and 1bit release flag.
+    Device can send two keycodes at once. If just one keycode is sent
+    keycode1 contains it and keyocode2 is 0xFF.
+
+    Power switch:
+    You can read the state from PSW line(active low) however
+    the switch has a special scancode 0x7F7F, so you can
+    also read from Data line. It uses 0xFFFF for release scancode.
+
+END_OF_ADB
diff --git a/adb.c b/adb.c
new file mode 100644
index 0000000000..e66a501b7c
--- /dev/null
+++ b/adb.c
@@ -0,0 +1,180 @@
+#include <stdbool.h>
+#include <util/delay.h>
+#include <avr/io.h>
+#include "adb.h"
+
+
+static inline void data_lo(void);
+static inline void data_hi(void);
+static inline bool data_in(void);
+#ifdef ADB_PSW_BIT
+static inline void psw_lo(void);
+static inline void psw_hi(void);
+static inline bool psw_in(void);
+#endif
+
+static inline void attention(void);
+static inline void place_bit0(void);
+static inline void place_bit1(void);
+static inline void send_byte(uint8_t data);
+static inline bool read_bit(void);
+static inline uint8_t read_byte(void);
+static inline uint8_t wait_data_lo(uint8_t us);
+static inline uint8_t wait_data_hi(uint8_t us);
+
+
+void adb_host_init(void)
+{
+    data_hi();
+#ifdef ADB_PSW_BIT
+    psw_hi();
+#endif
+}
+
+#ifdef ADB_PSW_BIT
+bool adb_host_psw(void)
+{
+    return psw_in();
+}
+#endif
+
+uint16_t adb_host_kbd_recv(void)
+{
+    uint16_t data = 0;
+    attention();
+    send_byte(0x2C);            // Addr:2, Cmd:talk(11), Reg:0(00)
+    place_bit0();               // Stopbit
+    if (!wait_data_lo(0xFF))    // Stop to Start(140-260us)
+        return 0;               // No data to send
+    if (!read_bit())            // Startbit(1)
+        return -2;
+    data = read_byte();
+    data = (data<<8) | read_byte();
+    if (read_bit())             // Stopbit(0)
+        return -3;
+    return data;
+}
+
+
+static inline void data_lo()
+{
+    ADB_DDR  |=  (1<<ADB_DATA_BIT);
+    ADB_PORT &= ~(1<<ADB_DATA_BIT);
+}
+static inline void data_hi()
+{
+    ADB_PORT |=  (1<<ADB_DATA_BIT);
+    ADB_DDR  &= ~(1<<ADB_DATA_BIT);
+}
+static inline bool data_in()
+{
+    ADB_PORT |=  (1<<ADB_DATA_BIT);
+    ADB_DDR  &= ~(1<<ADB_DATA_BIT);
+    return ADB_PIN&(1<<ADB_DATA_BIT);
+}
+
+#ifdef ADB_PSW_BIT
+static inline void psw_lo()
+{
+    ADB_DDR  |=  (1<<ADB_PSW_BIT);
+    ADB_PORT &= ~(1<<ADB_PSW_BIT);
+}
+static inline void psw_hi()
+{
+    ADB_PORT |=  (1<<ADB_PSW_BIT);
+    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
+}
+static inline bool psw_in()
+{
+    ADB_PORT |=  (1<<ADB_PSW_BIT);
+    ADB_DDR  &= ~(1<<ADB_PSW_BIT);
+    return ADB_PIN&(1<<ADB_PSW_BIT);
+}
+#endif
+
+static inline void attention(void)
+{
+    data_lo();
+    _delay_us(700);
+    place_bit1();
+}
+
+static inline void place_bit0(void)
+{
+    data_lo();
+    _delay_us(65);
+    data_hi();
+    _delay_us(35);
+}
+
+static inline void place_bit1(void)
+{
+    data_lo();
+    _delay_us(35);
+    data_hi();
+    _delay_us(65);
+}
+
+static inline void send_byte(uint8_t data)
+{
+    for (int i = 0; i < 8; i++) {
+        if (data&(0x80>>i))
+            place_bit1();
+        else
+            place_bit0();
+    }
+}
+
+static inline bool read_bit(void)
+{
+    // ADB Bit Cells
+    //
+    // bit0: ______~~~
+    //       65    :35us
+    //
+    // bit1: ___~~~~~~
+    //       35 :65us
+    //
+    // bit0 low time: 60-70% of bit cell(42-91us)
+    // bit1 low time: 30-40% of bit cell(21-52us)
+    // bit cell time: 70-130us
+    // [from Apple IIgs Hardware Reference Second Edition]
+    //
+    // After 55us if data line is low/high then bit is 0/1.
+    // Too simple to rely on?
+    bool bit;
+    wait_data_lo(75);   // wait the beginning of bit cell
+    _delay_us(55);
+    bit = data_in();
+    wait_data_hi(36);   // wait high part of bit cell
+    return bit;
+}
+
+static inline uint8_t read_byte(void)
+{
+    uint8_t data = 0;
+    for (int i = 0; i < 8; i++) {
+        data <<= 1;
+        if (read_bit())
+            data = data | 1;
+    }
+    return data;
+}
+
+static inline uint8_t wait_data_lo(uint8_t us)
+{
+    while (data_in() && us) {
+        _delay_us(1);
+        us--;
+    }
+    return us;
+}
+
+static inline uint8_t wait_data_hi(uint8_t us)
+{
+    while (!data_in() && us) {
+        _delay_us(1);
+        us--;
+    }
+    return us;
+}
diff --git a/adb.h b/adb.h
new file mode 100644
index 0000000000..8f16735470
--- /dev/null
+++ b/adb.h
@@ -0,0 +1,18 @@
+#ifndef ADB_H
+#define ADB_H
+
+#include <stdbool.h>
+
+#if !(defined(ADB_PORT) && \
+      defined(ADB_PIN)  && \
+      defined(ADB_DDR)  && \
+      defined(ADB_DATA_BIT))
+#   error "ADB port setting is required in config.h"
+#endif
+
+// ADB host
+void     adb_host_init(void);
+bool     adb_host_psw(void);
+uint16_t adb_host_kbd_recv(void);
+
+#endif
diff --git a/adb/Makefile b/adb/Makefile
new file mode 100644
index 0000000000..c27c75e15d
--- /dev/null
+++ b/adb/Makefile
@@ -0,0 +1,82 @@
+# Hey Emacs, this is a -*- makefile -*-
+#----------------------------------------------------------------------------
+# WinAVR Makefile Template written by Eric B. Weddington, Jörg Wunsch, et al.
+#
+# Released to the Public Domain
+#
+# Additional material for this makefile was written by:
+# Peter Fleury
+# Tim Henigan
+# Colin O'Flynn
+# Reiner Patommel
+# Markus Pfaff
+# Sander Pool
+# Frederik Rouleau
+# Carlos Lamas
+#
+#----------------------------------------------------------------------------
+# On command line:
+#
+# make all = Make software.
+#
+# make clean = Clean out built project files.
+#
+# make coff = Convert ELF to AVR COFF.
+#
+# make extcoff = Convert ELF to AVR Extended COFF.
+#
+# make program = Download the hex file to the device, using avrdude.
+#                Please customize the avrdude settings below first!
+#
+# make debug = Start either simulavr or avarice as specified for debugging, 
+#              with avr-gdb or avr-insight as the front end for debugging.
+#
+# make filename.s = Just compile filename.c into the assembler code only.
+#
+# make filename.i = Create a preprocessed source file for use in submitting
+#                   bug reports to the GCC project.
+#
+# To rebuild project do "make clean" then "make all".
+#----------------------------------------------------------------------------
+
+# Target file name (without extension).
+TARGET = tmk_adb
+
+# Directory common source filess exist
+COMMON_DIR = ..
+
+# Directory keyboard dependent files exist
+TARGET_DIR = .
+
+# keyboard dependent files
+TARGET_SRC =	keymap.c \
+  	        matrix.c \
+		adb.c
+
+
+# MCU name, you MUST set this to match the board you are using
+# type "make clean" after changing this, so all files will be rebuilt
+#MCU = at90usb162       # Teensy 1.0
+MCU = atmega32u4       # Teensy 2.0
+#MCU = at90usb646       # Teensy++ 1.0
+#MCU = at90usb1286      # Teensy++ 2.0
+
+
+# Processor frequency.
+#   Normally the first thing your program should do is set the clock prescaler,
+#   so your program will run at the correct speed.  You should also set this
+#   variable to same clock speed.  The _delay_ms() macro uses this, and many
+#   examples use this variable to calculate timings.  Do not add a "UL" here.
+F_CPU = 16000000
+
+
+# Build Options
+#   comment out to disable the options.
+#
+MOUSEKEY_ENABLE = yes	# Mouse keys
+#PS2_MOUSE_ENABLE = yes	# PS/2 mouse(TrackPoint) support
+USB_EXTRA_ENABLE = yes	# Enhanced feature for Windows(Audio control and System control)
+#USB_NKRO_ENABLE = yes	# USB Nkey Rollover
+
+
+include $(COMMON_DIR)/Makefile.common
diff --git a/adb/README b/adb/README
new file mode 100644
index 0000000000..19d9f8fa1f
--- /dev/null
+++ b/adb/README
@@ -0,0 +1,19 @@
+ADB to USB keyboard converter
+=============================
+
+This firmware converts ADB keyboard protocol to USB.
+
+Build
+-----
+0. Connect ADB keyboard to Teensy by 3 lines(Vcc, GND, Data).
+   PSW line is optional. See ADB.txt for details.
+1. Define following macros for ADB connection in config.h:
+   ADB_PORT
+   ADB_PIN
+   ADB_DDR
+   ADB_DATA_BIT
+   ADB_PSW_BIT
+2. make
+3. program Teensy.
+
+EOF
diff --git a/adb/config.h b/adb/config.h
new file mode 100644
index 0000000000..099a24bfa8
--- /dev/null
+++ b/adb/config.h
@@ -0,0 +1,47 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+/* controller configuration */
+#include "controller_teensy.h"
+
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x0ADB
+#define MANUFACTURER    t.m.k.
+#define PRODUCT         ADB keyboard converter
+#define DESCRIPTION     convert ADB keyboard to USB
+
+/* matrix size */
+#define MATRIX_ROWS 16  // keycode bit: 3-0
+#define MATRIX_COLS 8   // keycode bit: 6-4
+/* define if matrix has ghost */
+//#define MATRIX_HAS_GHOST
+
+/* USB NKey Rollover */
+#ifdef USB_NKRO_ENABLE
+#endif
+
+/* mouse keys */
+#ifdef MOUSEKEY_ENABLE
+#   define MOUSEKEY_DELAY_TIME 192
+#endif
+
+/* PS/2 mouse */
+#ifdef PS2_MOUSE_ENABLE
+#   define PS2_CLOCK_PORT  PORTF
+#   define PS2_CLOCK_PIN   PINF
+#   define PS2_CLOCK_DDR   DDRF
+#   define PS2_CLOCK_BIT   0
+#   define PS2_DATA_PORT   PORTF
+#   define PS2_DATA_PIN    PINF
+#   define PS2_DATA_DDR    DDRF
+#   define PS2_DATA_BIT    1
+#endif
+
+/* ADB port setting */
+#define ADB_PORT        PORTF
+#define ADB_PIN         PINF
+#define ADB_DDR         DDRF
+#define ADB_DATA_BIT    0
+//#define ADB_PSW_BIT     1       // optional
+
+#endif
diff --git a/adb/keymap.c b/adb/keymap.c
new file mode 100644
index 0000000000..8a9640482c
--- /dev/null
+++ b/adb/keymap.c
@@ -0,0 +1,135 @@
+/* 
+ * Keymap for ADB keyboard
+ */
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/pgmspace.h>
+#include "usb_keyboard.h"
+#include "usb_keycodes.h"
+#include "print.h"
+#include "debug.h"
+#include "util.h"
+#include "keymap_skel.h"
+
+
+// Convert physical keyboard layout to matrix array.
+// This is a macro to define keymap easily in keyboard layout form.
+
+// TODO: ADB to USB default keymap
+// TODO: keymap macro template for m0116/m0115
+/* Apple Keyboard m0116
+    K7F, \
+    K35, K12, K13, K14, K15, K17, K16, K1A, K1C, K19, K1D, K1B, K18, K33,       K47, K51, K4B, K43, \
+    K30, K0C, K0D, K0E, K0F, K10, K11, K20, K22, K1F, K23, K21, K1E,            K59, K5B, K5C, K4E, \
+    K36, K00, K01, K02, K03, K05, K04, K26, K28, K25, K29, K27,      K24,       K56, K57, K58, K45, \
+    K38, K06, K07, K08, K09, K0B, K2D, K2E, K2B, K2F, K2C,           K7B,       K53, K54, K55,      \
+    K39, K3A, K37, K32,           K31,           K2A, K3B, K3C, K3D, K3E,       K52,      K41, K4C  \
+*/
+
+/* no tenkey
+    K7F, \
+    K35, K12, K13, K14, K15, K17, K16, K1A, K1C, K19, K1D, K1B, K18, K33, \
+    K30, K0C, K0D, K0E, K0F, K10, K11, K20, K22, K1F, K23, K21, K1E,      \
+    K36, K00, K01, K02, K03, K05, K04, K26, K28, K25, K29, K27,      K24, \
+    K38, K06, K07, K08, K09, K0B, K2D, K2E, K2B, K2F, K2C,           K7B, \
+    K39, K3A, K37, K32,           K31,           K2A, K3B, K3C, K3D, K3E \
+*/
+#define KEYMAP( \
+    K7F, \
+    K35, K12, K13, K14, K15, K17, K16, K1A, K1C, K19, K1D, K1B, K18, K33, \
+    K30, K0C, K0D, K0E, K0F, K10, K11, K20, K22, K1F, K23, K21, K1E,      \
+    K36, K00, K01, K02, K03, K05, K04, K26, K28, K25, K29, K27,      K24, \
+    K38, K06, K07, K08, K09, K0B, K2D, K2E, K2B, K2F, K2C,           K7B, \
+    K39, K3A, K37, K32,           K31,           K2A, K3B, K3C, K3D, K3E  \
+) { \
+    { K00, K01, K02, K03, K04, K05, K06,  K07 }, \
+    { K08, K09, 000, K0B, K0C, K0D, K0E,  K0F }, \
+    { K10, K11, K12, K13, K14, K15, K16,  K17 }, \
+    { K18, K19, K1A, K1B, K1C, K1D, K1E,  K1F }, \
+    { K20, K21, K22, K23, K24, K25, K26,  K27 }, \
+    { K28, K29, K2A, K2B, K2C, K2D, K2E,  K2F }, \
+    { K30, K31, K32, K33, 000, K35, K36,  K37 }, \
+    { K38, K39, K3A, K3B, K3C, K3D, K3E,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, 000, 000, 000, 000,  000 }, \
+    { 000, 000, 000, K7B, 000, 000, 000,  K7F }, \
+}
+
+#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)]))
+
+
+// Assign Fn key(0-7) to a layer to which switch with the Fn key pressed.
+static const uint8_t PROGMEM fn_layer[] = {
+    0,              // FN_0
+    0,              // FN_1
+    0,              // FN_2
+    0,              // FN_3
+    0,              // FN_4
+    0,              // FN_5
+    0,              // FN_6
+    0               // FN_7
+};
+
+// Assign Fn key(0-7) to a keycode sent when release Fn key without use of the layer.
+// See layer.c for details.
+static const uint8_t PROGMEM fn_keycode[] = {
+    KB_NO,          // FN_0
+    KB_NO,          // FN_1
+    KB_NO,          // FN_2
+    KB_NO,          // FN_3
+    KB_NO,          // FN_4
+    KB_NO,          // FN_5
+    KB_NO,          // FN_6
+    KB_NO           // FN_7
+};
+
+static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* Layer 0: Default Layer
+     * ,---------------------------------------------------------.
+     * |Esc|  1|  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|Backs|
+     * |---------------------------------------------------------|
+     * |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|   |
+     * |-----------------------------------------------------'   |
+     * |Contro|  A|  S|  D|  F|  G|  H|  J|  K|  L|Fn3|  '|Return|
+     * |---------------------------------------------------------|
+     * |Shift   |  Z|  X|  C|  V|  B|  N|  M|  ,|  .|  /|Shift   |
+     * |---------------------------------------------------------|
+     * |Shi|Alt|Gui   l  `|                  |  \|Lef|Rig|Dow|Up |
+     * `---------------------------------------------------------'
+     */
+    KEYMAP(KB_PWR, \
+           KB_ESC, KB_1,   KB_2,   KB_3,   KB_4,   KB_5,   KB_6,   KB_7,   KB_8,   KB_9,   KB_0,   KB_MINS,KB_EQL, KB_BSPC, \
+           KB_TAB, KB_Q,   KB_W,   KB_E,   KB_R,   KB_T,   KB_Y,   KB_U,   KB_I,   KB_O,   KB_P,   KB_LBRC,KB_RBRC, \
+           KB_LCTL,KB_A,   KB_S,   KB_D,   KB_F,   KB_G,   KB_H,   KB_J,   KB_K,   KB_L,   KB_SCLN,KB_QUOT,KB_ENT, \
+           KB_LSFT,KB_Z,   KB_X,   KB_C,   KB_V,   KB_B,   KB_N,   KB_M,   KB_COMM,KB_DOT, KB_SLSH,KB_RSFT, \
+           KB_LSFT,KB_LALT,KB_LGUI,KB_GRV, KB_SPC, KB_BSLS,KB_LEFT,KB_RGHT,KB_DOWN,KB_UP),
+
+};
+
+
+uint8_t keymap_get_keycode(uint8_t layer, uint8_t row, uint8_t col)
+{
+    return KEYCODE(layer, row, col);
+}
+
+uint8_t keymap_fn_layer(uint8_t fn_bits)
+{
+    return pgm_read_byte(&fn_layer[biton(fn_bits)]);
+}
+
+uint8_t keymap_fn_keycode(uint8_t fn_bits)
+{
+    return pgm_read_byte(&fn_keycode[(biton(fn_bits))]);
+}
+
+// define a condition to enter special function mode
+bool keymap_is_special_mode(uint8_t fn_bits)
+{
+    //return (usb_keyboard_mods == (BIT_LCTRL | BIT_LSHIFT | BIT_LALT | BIT_LGUI));
+    return (usb_keyboard_mods == (BIT_RSHIFT));
+}
diff --git a/adb/matrix.c b/adb/matrix.c
new file mode 100644
index 0000000000..d0643371e2
--- /dev/null
+++ b/adb/matrix.c
@@ -0,0 +1,194 @@
+/*
+ * scan matrix
+ */
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include "print.h"
+#include "util.h"
+#include "debug.h"
+#include "adb.h"
+#include "matrix_skel.h"
+
+
+#if (MATRIX_COLS > 16)
+#   error "MATRIX_COLS must not exceed 16"
+#endif
+#if (MATRIX_ROWS > 255)
+#   error "MATRIX_ROWS must not exceed 255"
+#endif
+
+
+static bool _matrix_is_modified = false;
+
+// matrix state buffer(1:on, 0:off)
+#if (MATRIX_COLS <= 8)
+static uint8_t *matrix;
+static uint8_t _matrix0[MATRIX_ROWS];
+#else
+static uint16_t *matrix;
+static uint16_t _matrix0[MATRIX_ROWS];
+#endif
+
+#ifdef MATRIX_HAS_GHOST
+static bool matrix_has_ghost_in_row(uint8_t row);
+#endif
+static void _register_key(uint8_t key);
+
+
+inline
+uint8_t matrix_rows(void)
+{
+    return MATRIX_ROWS;
+}
+
+inline
+uint8_t matrix_cols(void)
+{
+    return MATRIX_COLS;
+}
+
+void matrix_init(void)
+{
+    adb_host_init();
+
+    // initialize matrix state: all keys off
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
+    matrix = _matrix0;
+
+    print_enable = true;
+    debug_enable = true;
+    debug_matrix = true;
+    debug_keyboard = true;
+    debug_mouse = true;
+    print("debug enabled.\n");
+    return;
+}
+
+uint8_t matrix_scan(void)
+{
+    uint16_t codes;
+    uint8_t key0, key1;
+
+    _matrix_is_modified = false;
+
+    codes = adb_host_kbd_recv();
+    key0 = codes>>8;
+    key1 = codes&0xFF;
+    if (debug_matrix) {
+        //print("adb_host_kbd_recv: "); phex16(codes); print("\n");
+    }
+
+    if (codes == 0) {                           // no keys
+        return 0;
+    } else if (key0 == 0xFF && key1 != 0xFF) {  // error
+        return codes&0xFF;
+    } else {
+        _matrix_is_modified = true;
+        _register_key(key0);
+        if (key1 != 0xFF)       // key1 is 0xFF when no second key.
+            _register_key(key1);
+    }
+
+    return 1;
+}
+
+bool matrix_is_modified(void)
+{
+    return _matrix_is_modified;
+}
+
+inline
+bool matrix_has_ghost(void)
+{
+#ifdef MATRIX_HAS_GHOST
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+        if (matrix_has_ghost_in_row(i))
+            return true;
+    }
+#endif
+    return false;
+}
+
+inline
+bool matrix_is_on(uint8_t row, uint8_t col)
+{
+    return (matrix[row] & (1<<col));
+}
+
+inline
+#if (MATRIX_COLS <= 8)
+uint8_t matrix_get_row(uint8_t row)
+#else
+uint16_t matrix_get_row(uint8_t row)
+#endif
+{
+    return matrix[row];
+}
+
+void matrix_print(void)
+{
+#if (MATRIX_COLS <= 8)
+    print("\nr/c 01234567\n");
+#else
+    print("\nr/c 0123456789ABCDEF\n");
+#endif
+    for (uint8_t row = 0; row < matrix_rows(); row++) {
+        phex(row); print(": ");
+#if (MATRIX_COLS <= 8)
+        pbin_reverse(matrix_get_row(row));
+#else
+        pbin_reverse16(matrix_get_row(row));
+#endif
+#ifdef MATRIX_HAS_GHOST
+        if (matrix_has_ghost_in_row(row)) {
+            print(" <ghost");
+        }
+#endif
+        print("\n");
+    }
+}
+
+uint8_t matrix_key_count(void)
+{
+    uint8_t count = 0;
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+#if (MATRIX_COLS <= 8)
+        count += bitpop(matrix[i]);
+#else
+        count += bitpop16(matrix[i]);
+#endif
+    }
+    return count;
+}
+
+#ifdef MATRIX_HAS_GHOST
+inline
+static bool matrix_has_ghost_in_row(uint8_t row)
+{
+    // no ghost exists in case less than 2 keys on
+    if (((matrix[row] - 1) & matrix[row]) == 0)
+        return false;
+
+    // ghost exists in case same state as other row
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+        if (i != row && (matrix[i] & matrix[row]) == matrix[row])
+            return true;
+    }
+    return false;
+}
+#endif
+
+inline
+static void _register_key(uint8_t key)
+{
+    uint8_t col, row;
+    col = key&0x07;
+    row = (key>>3)&0x0F;
+    if (key&0x80) {
+        matrix[row] &= ~(1<<col);
+    } else {
+        matrix[row] |=  (1<<col);
+    }
+}