Add Initial files of 4704_usb

10 files changed, 792 insertions, 0 deletions

diff --git a/converter/ibm4704_usb/Makefile b/converter/ibm4704_usb/Makefile
new file mode 100644
index 000000000..bc0f9fde7
--- /dev/null
+++ b/converter/ibm4704_usb/Makefile
@@ -0,0 +1,93 @@
+# Target file name (without extension).
+TARGET = ibm4704_usb
+
+# Directory common source filess exist
+TOP_DIR = ../..
+
+# Directory keyboard dependent files exist
+TARGET_DIR = .
+
+# project specific files
+SRC =   keymap_common.c \
+        matrix.c \
+        led.c \
+        protocol/ibm4704.c
+
+ifdef KEYMAP
+    SRC := keymap_$(KEYMAP).c $(SRC)
+else
+    SRC := keymap_plain.c $(SRC)
+endif
+
+CONFIG_H = config.h
+
+
+# MCU name
+#MCU = at90usb1287
+MCU = atmega32u4
+
+# Processor frequency.
+#     This will define a symbol, F_CPU, in all source code files equal to the
+#     processor frequency in Hz. You can then use this symbol in your source code to
+#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
+#     automatically to create a 32-bit value in your source code.
+#
+#     This will be an integer division of F_USB below, as it is sourced by
+#     F_USB after it has run through any CPU prescalers. Note that this value
+#     does not *change* the processor frequency - it should merely be updated to
+#     reflect the processor speed set externally so that the code can use accurate
+#     software delays.
+F_CPU = 16000000
+
+
+#
+# LUFA specific
+#
+# Target architecture (see library "Board Types" documentation).
+ARCH = AVR8
+
+# Input clock frequency.
+#     This will define a symbol, F_USB, in all source code files equal to the
+#     input clock frequency (before any prescaling is performed) in Hz. This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_USB = $(F_CPU)
+
+# Interrupt driven control endpoint task(+60)
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
+
+# Boot Section Size in *bytes*
+#   Teensy halfKay   512
+#   Teensy++ halfKay 1024
+#   Atmel DFU loader 4096
+#   LUFA bootloader  4096
+#   USBaspLoader     2048
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
+
+
+# Build Options
+#   comment out to disable the options.
+#
+#BOOTMAGIC_ENABLE = yes # Virtual DIP switch configuration(+1000)
+#MOUSEKEY_ENABLE = yes  # Mouse keys(+4700)
+##EXTRAKEY_ENABLE = yes # Audio control and System control(+450)
+CONSOLE_ENABLE = yes    # Console for debug(+400)
+COMMAND_ENABLE = yes    # Commands for debug and configuration
+#NKRO_ENABLE = yes      # USB Nkey Rollover - not yet supported in LUFA
+
+
+# Search Path
+VPATH += $(TARGET_DIR)
+VPATH += $(TOP_DIR)
+
+include $(TOP_DIR)/protocol.mk
+include $(TOP_DIR)/protocol/lufa.mk
+include $(TOP_DIR)/common.mk
+include $(TOP_DIR)/rules.mk
diff --git a/converter/ibm4704_usb/README.md b/converter/ibm4704_usb/README.md
new file mode 100644
index 000000000..1e29945d0
--- /dev/null
+++ b/converter/ibm4704_usb/README.md
@@ -0,0 +1,31 @@
+IBM 4704 to USB keyboard converter
+=======----=======================
+This firmware converts IBM 4704 keyboard protocol to USB HID.
+
+
+Connect Wires
+-------------
+In case of Teensy2.0(ATMega32U4):
+
+1. Connect Vcc and GND.
+2. Connect Clock and Data line. 
+    - Clock is on PD1 and Data on PD2.
+3. Optionally you need pull-up register. 1KOhm is OK?
+
+To change pin configuration edit config.h.
+
+
+Build Firmware
+--------------
+Just run `make`:
+
+    $ make
+
+To select keymap:
+
+    $ make KEYMAP=[plain|...]
+
+
+Keymap
+------
+Several version of keymap are available in advance but you are recommended to define your favorite layout yourself. To define your own keymap create file named `keymap_<name>.c` and see keymap document(you can find in top README.md) and existent keymap files.
diff --git a/converter/ibm4704_usb/config.h b/converter/ibm4704_usb/config.h
new file mode 100644
index 000000000..8c2d08f6f
--- /dev/null
+++ b/converter/ibm4704_usb/config.h
@@ -0,0 +1,73 @@
+/*
+Copyright 2014 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include <avr/interrupt.h>
+
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x4707
+#define DEVICE_VER      0x0001
+#define MANUFACTURER    t.m.k.
+#define PRODUCT         IBM 4704 keyboard converter
+#define DESCRIPTION     convert IBM 4704 keyboard to USB
+
+
+/* matrix size */
+#define MATRIX_ROWS 16  // keycode bit3-6 
+#define MATRIX_COLS 8   // keycode bit0-2
+
+
+/* key combination for command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)
+
+
+
+/*
+ * Busywait
+ */
+#define IBM4704_CLOCK_PORT  PORTD
+#define IBM4704_CLOCK_PIN   PIND
+#define IBM4704_CLOCK_DDR   DDRD
+#define IBM4704_CLOCK_BIT   1
+#define IBM4704_DATA_PORT   PORTD
+#define IBM4704_DATA_PIN    PIND
+#define IBM4704_DATA_DDR    DDRD
+#define IBM4704_DATA_BIT    2
+
+/*
+ * Pin interrupt
+ */
+#ifdef IBM4704_USE_INT
+#define IBM4704_INT_INIT()  do {    \
+    EICRA |= ((1<<ISC11) |      \
+              (0<<ISC10));      \
+} while (0)
+#define IBM4704_INT_ON()  do {      \
+    EIMSK |= (1<<INT1);         \
+} while (0)
+#define IBM4704_INT_OFF() do {      \
+    EIMSK &= ~(1<<INT1);        \
+} while (0)
+#define IBM4704_INT_VECT    INT1_vect
+#endif
+
+
+#endif
diff --git a/converter/ibm4704_usb/keymap_common.c b/converter/ibm4704_usb/keymap_common.c
new file mode 100644
index 000000000..241d2e33b
--- /dev/null
+++ b/converter/ibm4704_usb/keymap_common.c
@@ -0,0 +1,30 @@
+/*
+Copyright 2011,2012,2013 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "keymap_common.h"
+
+
+/* translates key to keycode */
+uint8_t keymap_key_to_keycode(uint8_t layer, key_t key)
+{
+    return pgm_read_byte(&keymaps[(layer)][(key.row)][(key.col)]);
+}
+
+/* translates Fn keycode to action */
+action_t keymap_fn_to_action(uint8_t keycode)
+{
+    return (action_t){ .code = pgm_read_word(&fn_actions[FN_INDEX(keycode)]) };
+}
diff --git a/converter/ibm4704_usb/keymap_common.h b/converter/ibm4704_usb/keymap_common.h
new file mode 100644
index 000000000..8955baeb5
--- /dev/null
+++ b/converter/ibm4704_usb/keymap_common.h
@@ -0,0 +1,73 @@
+/*
+Copyright 2011,2012,2013 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef KEYMAP_COMMON_H
+#define KEYMAP_COMMON_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/pgmspace.h>
+#include "keycode.h"
+#include "action.h"
+#include "action_macro.h"
+#include "report.h"
+#include "print.h"
+#include "debug.h"
+#include "keymap.h"
+
+
+// 32*8(256) byte array which converts PS/2 code into USB code
+extern const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS];
+extern const uint16_t fn_actions[];
+
+
+/* Original keys */
+#define KEYMAP( \
+    K00,K18,K19,K1A,K10,K11,K12,K08,K09,K0A,K0F,K1F,K0D,K0C,K0E, \
+    K04,K05,K06,K13,K14,K15,K16,K17,K01,K02,K03,K1B,K1C,K1D, \
+    K20,K21,K22,K23,K24,K25,K26,K27,K28,K29,K2A,K2B,K2C,K2D, \
+    K30,K3E,K32,K33,K34,K35,K36,K37,K38,K39,K3A,K3B,K3D, \
+    K31,K41,K3F,        K40,                    K42,K2F \
+) { \
+    { KC_##K00, KC_##K01, KC_##K02, KC_##K03, KC_##K04, KC_##K05, KC_##K06, KC_NO }, \
+    { KC_##K08, KC_##K09, KC_##K0A, KC_NO,    KC_##K0C, KC_##K0D, KC_##K0E, KC_##K0F }, \
+    { KC_##K10, KC_##K11, KC_##K12, KC_##K13, KC_##K14, KC_##K15, KC_##K16, KC_##K17 }, \
+    { KC_##K18, KC_##K19, KC_##K1A, KC_##K1B, KC_##K1C, KC_##K1D, KC_NO,    KC_##K1F }, \
+    { KC_##K20, KC_##K21, KC_##K22, KC_##K23, KC_##K24, KC_##K25, KC_##K26, KC_##K27 }, \
+    { KC_##K28, KC_##K29, KC_##K2A, KC_##K2B, KC_##K2C, KC_##K2D, KC_NO,    KC_##K2F }, \
+    { KC_##K30, KC_##K31, KC_##K32, KC_##K33, KC_##K34, KC_##K35, KC_##K36, KC_##K37 }, \
+    { KC_##K38, KC_##K39, KC_##K3A, KC_##K3B, KC_NO,    KC_##K3D, KC_##K3E, KC_##K3F }, \
+    { KC_##K40, KC_##K41, KC_##K42, KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+    { KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO,    KC_NO }, \
+}
+
+#endif
+
+/*
+    { K48, K49, K4A, K4B, K4C, K4D, K4E, K4F }, \
+    { K50, K51, K52, K53, K54, K55, K56, K57 }, \
+    { K58, K59, K5A, K5B, K5C, K5D, K5E, K5F }, \
+    { K60, K61, K62, K63, K64, K65, K66, K67 }, \
+    { K68, K69, K6A, K6B, K6C, K6D, K6E, K6F }, \
+    { K70, K71, K72, K73, K74, K75, K76, K77 }, \
+    { K78, K79, K7A, K7B, K7C, K7D, K7E, K7F }, \
+*/
diff --git a/converter/ibm4704_usb/keymap_plain.c b/converter/ibm4704_usb/keymap_plain.c
new file mode 100644
index 000000000..0ca4f14c1
--- /dev/null
+++ b/converter/ibm4704_usb/keymap_plain.c
@@ -0,0 +1,28 @@
+#include "keymap_common.h"
+
+
+const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* 0: default
+     * ,-----------------------------------------------------------.
+     * |  `|  1|  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|???|BS |
+     * |-----------------------------------------------------------|
+     * |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|    \|
+     * |-----------------------------------------------------------|
+     * |Ctrl  |  A|  S|  D|  F|  G|  H|  J|  K|  L|  ;|  '|???|Ret |
+     * |-----------------------------------------------------------|
+     * |Shif|???|  Z|  X|  C|  V|  B|  N|  M|  ,|  ,|  /|???|Shift |
+     * |-----------------------------------------------------------|
+     * |Ctrl |Gui|Alt  |         Space             |Alt  |Gui|Ctrl |
+     * `-----------------------------------------------------------'
+     */
+    KEYMAP(
+    ESC, 1,   2,   3,   4,   5,   6,   7,   8,   9,   0,   MINS,EQL, BSLS,GRV, \
+    TAB, Q,   W,   E,   R,   T,   Y,   U,   I,   O,   P,   LBRC,RBRC,BSPC, \
+    LCTL,A,   S,   D,   F,   G,   H,   J,   K,   L,   SCLN,QUOT,NO,  ENT, \
+    LSFT,NO,  Z,   X,   C,   V,   B,   N,   M,   COMM,DOT, SLSH,     RSFT, \
+    LCTL,LGUI,LALT,          SPC,                               RGUI,RCTL \
+    ),
+};
+
+const uint16_t PROGMEM fn_actions[] = {
+};
diff --git a/converter/ibm4704_usb/led.c b/converter/ibm4704_usb/led.c
new file mode 100644
index 000000000..f76545f0b
--- /dev/null
+++ b/converter/ibm4704_usb/led.c
@@ -0,0 +1,24 @@
+/*
+Copyright 2011 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "stdint.h"
+#include "led.h"
+
+
+void led_set(uint8_t usb_led)
+{
+}
diff --git a/converter/ibm4704_usb/matrix.c b/converter/ibm4704_usb/matrix.c
new file mode 100644
index 000000000..796e2d064
--- /dev/null
+++ b/converter/ibm4704_usb/matrix.c
@@ -0,0 +1,179 @@
+/*
+Copyright 2014 Jun Wako <wakojun@gmail.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include "action.h"
+#include "print.h"
+#include "debug.h"
+#include "util.h"
+#include "ibm4704.h"
+#include "matrix.h"
+
+
+static void matrix_make(uint8_t code);
+static void matrix_break(uint8_t code);
+static void matrix_clear(void);
+
+
+/*
+ * Matrix Array usage:
+ * IBM 4704 scan codes are assigned into 128(16x8)-cell matrix.
+ *
+ *    8bit wide
+ *   +---------+
+ *  0|         |
+ *  :|   XX    | 00-7F
+ *  f|         |
+ *   +---------+
+ *
+ * Exceptions:
+ */
+static uint8_t matrix[MATRIX_ROWS];
+
+// scan code bits  7654 3210
+// R:row/C:column  -RRR RCCC
+#define ROW(code)      ((code>>3)&0x0f)
+#define COL(code)      (code&0x07)
+
+
+inline
+uint8_t matrix_rows(void)
+{
+    return MATRIX_ROWS;
+}
+
+inline
+uint8_t matrix_cols(void)
+{
+    return MATRIX_COLS;
+}
+
+static void enable_break(void)
+{
+    uint8_t ret;
+    for (uint8_t code = 0; code < 0x80; code++) {
+        while (ibm4704_send(0x80|code) != 0) {
+            print("z");
+        }
+        _delay_ms(1);
+        ret = ibm4704_recv(); 
+        if (ret!=0xFF) {
+            xprintf("%0X: %0X ", code, ret);
+        }
+    }
+    _delay_us(100);
+    print("End\n");
+    while (ibm4704_send(0xFF) != 0) {
+        print("Z");
+    } // End
+}
+
+void matrix_init(void)
+{
+    debug_enable = true;
+
+    ibm4704_init();
+    matrix_clear();
+
+    xprintf("------\n");
+    enable_break();
+    //while (ibm4704_send(0x8C) != 0) ;
+    //while (ibm4704_send(0xFF) != 0) ;
+}
+
+/*
+ * IBM 4704 Scan Code
+ */
+uint8_t matrix_scan(void)
+{
+    uint8_t code = ibm4704_recv();
+    if (code==0xFF) {
+        // Not receivd
+        return 0;
+    } else if ((code&0x78)==0x78) {
+        // 0xFF-F8 and 0x7F-78 is not scan code
+        dprintf("Error: %0X\n", code);
+        matrix_clear();
+        return 0;
+    } else if (code&0x80) {
+        matrix_make(code);
+    } else {
+        matrix_break(code);
+    }
+    return 1;
+}
+
+inline
+bool matrix_has_ghost(void)
+{
+    return false;
+}
+
+inline
+bool matrix_is_on(uint8_t row, uint8_t col)
+{
+    return (matrix[row] & (1<<col));
+}
+
+inline
+uint8_t matrix_get_row(uint8_t row)
+{
+    return matrix[row];
+}
+
+void matrix_print(void)
+{
+    print("\nr/c 01234567\n");
+    for (uint8_t row = 0; row < matrix_rows(); row++) {
+        // TODO: use new function
+        phex(row); print(": ");
+        pbin_reverse(matrix_get_row(row));
+        print("\n");
+    }
+}
+
+uint8_t matrix_key_count(void)
+{
+    uint8_t count = 0;
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+        count += bitpop(matrix[i]);
+    }
+    return count;
+}
+
+
+
+inline
+static void matrix_make(uint8_t code)
+{
+    matrix[ROW(code)] |= 1<<COL(code);
+}
+
+inline
+static void matrix_break(uint8_t code)
+{
+    matrix[ROW(code)] &= ~(1<<COL(code));
+}
+
+inline
+static void matrix_clear(void)
+{
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
+}
diff --git a/protocol/ibm4704.c b/protocol/ibm4704.c
new file mode 100644
index 000000000..26441ed52
--- /dev/null
+++ b/protocol/ibm4704.c
@@ -0,0 +1,150 @@
+/*
+Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
+*/
+#include <stdbool.h>
+#include <util/delay.h>
+#include "debug.h"
+#include "ibm4704.h"
+
+
+#define WAIT(stat, us, err) do { \
+    if (!wait_##stat(us)) { \
+        ibm4704_error = err; \
+        goto ERROR; \
+    } \
+} while (0)
+
+
+uint8_t ibm4704_error = 0;
+
+
+void ibm4704_init(void)
+{
+    // POR
+    //_delay_ms(2500);
+    //while ( 0xA3 != ibm4704_recv() ) ;
+
+    inhibit();
+    DDRD |= 1<<3;
+    PORTD &= ~(1<<3);
+}
+
+uint8_t ibm4704_send(uint8_t data)
+{
+    bool parity = true; // odd parity
+    ibm4704_error = 0;
+
+    /* Request to send */
+    idle();
+    clock_lo();
+PIND |= 1<<3;
+
+    /* wait for Start bit(Clock:lo/Data:hi) */
+    WAIT(data_hi, 300, 0x30);
+
+    /* Data bit */
+    for (uint8_t i = 0; i < 8; i++) {
+        WAIT(clock_hi, 100, 0x31);
+        //_delay_us(5);
+PIND |= 1<<3;
+        if (data&(1<<i)) {
+            parity = !parity;
+            data_hi();
+        } else {
+            data_lo();
+        }
+        WAIT(clock_lo, 100, 0x32);
+    }
+
+    /* Parity bit */
+    WAIT(clock_hi, 100, 4);
+PIND |= 1<<3;
+    if (parity) { data_hi(); } else { data_lo(); }
+    WAIT(clock_lo, 100, 5);
+
+    /* Stop bit */
+    WAIT(clock_hi, 100, 4);
+    data_hi();
+
+    /* End */
+    WAIT(data_lo, 100, 6);
+
+    inhibit();
+    _delay_us(200); // wait to recover clock to hi
+    return 0;
+ERROR:
+    inhibit();
+xprintf("x%02X ", ibm4704_error);
+    _delay_us(200); // wait to recover clock to hi
+    return -1;
+}
+
+/* receive data when host want else inhibit communication */
+uint8_t ibm4704_recv_response(void)
+{
+    // 250 * 100us(wait start bit in ibm4704_recv)
+    uint8_t data = 0;
+    uint8_t try = 250;
+    do {
+        data = ibm4704_recv();
+    } while (try-- && ibm4704_error);
+    return data;
+}
+
+/*
+Keyboard to Host:
+Clock   ~~~~___~~_~~_~~_~~_~~_~~_~~_~~_~~_~~~~~~~~ H:60us/L:30us
+
+Data    ____~~X==X==X==X==X==X==X==X==X==X________
+            |  0  1  2  3  4  5  6  7  P(odd)
+            |  LSB                MSB
+            Start bit(80us)
+*/
+uint8_t ibm4704_recv(void)
+{
+    uint8_t data = 0;
+    bool parity = true;    // odd parity
+    ibm4704_error = IBM4704_ERR_NONE;
+
+    idle();
+    _delay_us(5);   // wait for line settles
+
+    /* start bit */
+    WAIT(clock_lo, 100, 1); // wait for keyboard to send
+    WAIT(data_hi, 100, 2);  // can be delayed that long
+
+    WAIT(clock_hi, 100, 3); // first rising edge which can take longer
+    /* data */
+    for (uint8_t i = 0; i < 8; i++) {
+        WAIT(clock_hi, 100, 0x20+i);
+        //_delay_us(5);
+        if (data_in()) {
+            parity = !parity;
+            data |= (1<<i);
+        }
+        WAIT(clock_lo, 150, 0x28+i);
+    }
+
+    /* parity */
+    WAIT(clock_hi, 100, 7);
+    if (data_in() != parity) {
+        ibm4704_error = IBM4704_ERR_PARITY;
+        goto ERROR;
+    }
+    WAIT(clock_lo, 150, 8);
+
+    /* stop bit */
+    WAIT(clock_hi, 100, 9);
+    WAIT(data_lo, 1, 9);
+
+    inhibit();
+    _delay_us(200); // wait to recover clock to hi
+    return data;
+ERROR:
+    if (ibm4704_error > 2) {
+        xprintf("x%02X ", ibm4704_error);
+    }
+    inhibit();
+    _delay_us(200); // wait to recover clock to hi
+    return -1;
+}
diff --git a/protocol/ibm4704.h b/protocol/ibm4704.h
new file mode 100644
index 000000000..ff8a5b771
--- /dev/null
+++ b/protocol/ibm4704.h
@@ -0,0 +1,111 @@
+/*
+Copyright 2014 Jun WAKO <wakojun@gmail.com>
+*/
+#ifndef IBM4704_H
+#define IBM4704_H
+
+#define IBM4704_ERR_NONE        0
+#define IBM4704_ERR_STARTBIT    1
+#define IBM4704_ERR_PARITY      0x70
+
+
+void ibm4704_init(void);
+uint8_t ibm4704_send(uint8_t data);
+uint8_t ibm4704_recv_response(void);
+uint8_t ibm4704_recv(void);
+
+
+/* Check pin configuration */
+#if !(defined(IBM4704_CLOCK_PORT) && \
+      defined(IBM4704_CLOCK_PIN) && \
+      defined(IBM4704_CLOCK_DDR) && \
+      defined(IBM4704_CLOCK_BIT))
+#   error "ibm4704 clock pin configuration is required in config.h"
+#endif
+
+#if !(defined(IBM4704_DATA_PORT) && \
+      defined(IBM4704_DATA_PIN) && \
+      defined(IBM4704_DATA_DDR) && \
+      defined(IBM4704_DATA_BIT))
+#   error "ibm4704 data pin configuration is required in config.h"
+#endif
+
+
+/*--------------------------------------------------------------------
+ * static functions
+ *------------------------------------------------------------------*/
+static inline void clock_lo(void)
+{
+    IBM4704_CLOCK_PORT &= ~(1<<IBM4704_CLOCK_BIT);
+    IBM4704_CLOCK_DDR  |=  (1<<IBM4704_CLOCK_BIT);
+}
+static inline void clock_hi(void)
+{
+    /* input with pull up */
+    IBM4704_CLOCK_DDR  &= ~(1<<IBM4704_CLOCK_BIT);
+    IBM4704_CLOCK_PORT |=  (1<<IBM4704_CLOCK_BIT);
+}
+static inline bool clock_in(void)
+{
+    IBM4704_CLOCK_DDR  &= ~(1<<IBM4704_CLOCK_BIT);
+    IBM4704_CLOCK_PORT |=  (1<<IBM4704_CLOCK_BIT);
+    _delay_us(1);
+    return IBM4704_CLOCK_PIN&(1<<IBM4704_CLOCK_BIT);
+}
+static inline void data_lo(void)
+{
+    IBM4704_DATA_PORT &= ~(1<<IBM4704_DATA_BIT);
+    IBM4704_DATA_DDR  |=  (1<<IBM4704_DATA_BIT);
+}
+static inline void data_hi(void)
+{
+    /* input with pull up */
+    IBM4704_DATA_DDR  &= ~(1<<IBM4704_DATA_BIT);
+    IBM4704_DATA_PORT |=  (1<<IBM4704_DATA_BIT);
+}
+static inline bool data_in(void)
+{
+    IBM4704_DATA_DDR  &= ~(1<<IBM4704_DATA_BIT);
+    IBM4704_DATA_PORT |=  (1<<IBM4704_DATA_BIT);
+    _delay_us(1);
+    return IBM4704_DATA_PIN&(1<<IBM4704_DATA_BIT);
+}
+
+static inline uint16_t wait_clock_lo(uint16_t us)
+{
+    while (clock_in()  && us) { asm(""); _delay_us(1); us--; }
+    return us;
+}
+static inline uint16_t wait_clock_hi(uint16_t us)
+{
+    while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
+    return us;
+}
+static inline uint16_t wait_data_lo(uint16_t us)
+{
+    while (data_in() && us)  { asm(""); _delay_us(1); us--; }
+    return us;
+}
+static inline uint16_t wait_data_hi(uint16_t us)
+{
+    while (!data_in() && us)  { asm(""); _delay_us(1); us--; }
+    return us;
+}
+
+/* idle state that device can send */
+static inline void idle(void)
+{
+    clock_hi();
+    data_hi();
+}
+
+/* inhibit device to send 
+ * keyboard checks Data line on start bit(Data:hi) and it stops sending if Data line is low.
+ */
+static inline void inhibit(void)
+{
+    clock_hi();
+    data_lo();
+}
+
+#endif