// PC keyboard interface constants

#define KBSTATP         0x64    // kbd controller status port(I)
#define KBS_DIB         0x01    // kbd data in buffer
#define KBDATAP         0x60    // kbd data port(I)

#define NO              0

#define SHIFT           (1<<0)
#define CTL             (1<<1)
#define ALT             (1<<2)

#define CAPSLOCK        (1<<3)
#define NUMLOCK         (1<<4)
#define SCROLLLOCK      (1<<5)

#define E0ESC           (1<<6)

// Special keycodes
#define KEY_HOME        0xE0
#define KEY_END         0xE1
#define KEY_UP          0xE2
#define KEY_DN          0xE3
#define KEY_LF          0xE4
#define KEY_RT          0xE5
#define KEY_PGUP        0xE6
#define KEY_PGDN        0xE7
#define KEY_INS         0xE8
#define KEY_DEL         0xE9

// C('A') == Control-A
#define C(x) (x - '@')

static uchar shiftcode[256] =
{
  [0x1D] = CTL,
  [0x2A] = SHIFT,
  [0x36] = SHIFT,
  [0x38] = ALT,
  [0x9D] = CTL,
  [0xB8] = ALT
};

static uchar togglecode[256] =
{
  [0x3A] = CAPSLOCK,
  [0x45] = NUMLOCK,
  [0x46] = SCROLLLOCK
};

static uchar normalmap[256] =
{
  NO,   0x1B, '1',  '2',  '3',  '4',  '5',  '6',  // 0x00
  '7',  '8',  '9',  '0',  '-',  '=',  '\b', '\t',
  'q',  'w',  'e',  'r',  't',  'y',  'u',  'i',  // 0x10
  'o',  'p',  '[',  ']',  '\n', NO,   'a',  's',
  'd',  'f',  'g',  'h',  'j',  'k',  'l',  ';',  // 0x20
  '\'', '`',  NO,   '\\', 'z',  'x',  'c',  'v',
  'b',  'n',  'm',  ',',  '.',  '/',  NO,   '*',  // 0x30
  NO,   ' ',  NO,   NO,   NO,   NO,   NO,   NO,
  NO,   NO,   NO,   NO,   NO,   NO,   NO,   '7',  // 0x40
  '8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',
  '2',  '3',  '0',  '.',  NO,   NO,   NO,   NO,   // 0x50
  [0x9C] = '\n',      // KP_Enter
  [0xB5] = '/',       // KP_Div
  [0xC8] = KEY_UP,    [0xD0] = KEY_DN,
  [0xC9] = KEY_PGUP,  [0xD1] = KEY_PGDN,
  [0xCB] = KEY_LF,    [0xCD] = KEY_RT,
  [0x97] = KEY_HOME,  [0xCF] = KEY_END,
  [0xD2] = KEY_INS,   [0xD3] = KEY_DEL
};

static uchar shiftmap[256] =
{
  NO,   033,  '!',  '@',  '#',  '$',  '%',  '^',  // 0x00
  '&',  '*',  '(',  ')',  '_',  '+',  '\b', '\t',
  'Q',  'W',  'E',  'R',  'T',  'Y',  'U',  'I',  // 0x10
  'O',  'P',  '{',  '}',  '\n', NO,   'A',  'S',
  'D',  'F',  'G',  'H',  'J',  'K',  'L',  ':',  // 0x20
  '"',  '~',  NO,   '|',  'Z',  'X',  'C',  'V',
  'B',  'N',  'M',  '<',  '>',  '?',  NO,   '*',  // 0x30
  NO,   ' ',  NO,   NO,   NO,   NO,   NO,   NO,
  NO,   NO,   NO,   NO,   NO,   NO,   NO,   '7',  // 0x40
  '8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',
  '2',  '3',  '0',  '.',  NO,   NO,   NO,   NO,   // 0x50
  [0x9C] = '\n',      // KP_Enter
  [0xB5] = '/',       // KP_Div
  [0xC8] = KEY_UP,    [0xD0] = KEY_DN,
  [0xC9] = KEY_PGUP,  [0xD1] = KEY_PGDN,
  [0xCB] = KEY_LF,    [0xCD] = KEY_RT,
  [0x97] = KEY_HOME,  [0xCF] = KEY_END,
  [0xD2] = KEY_INS,   [0xD3] = KEY_DEL
};

static uchar ctlmap[256] =
{
  NO,      NO,      NO,      NO,      NO,      NO,      NO,      NO,
  NO,      NO,      NO,      NO,      NO,      NO,      NO,      NO,
  C('Q'),  C('W'),  C('E'),  C('R'),  C('T'),  C('Y'),  C('U'),  C('I'),
  C('O'),  C('P'),  NO,      NO,      '\r',    NO,      C('A'),  C('S'),
  C('D'),  C('F'),  C('G'),  C('H'),  C('J'),  C('K'),  C('L'),  NO,
  NO,      NO,      NO,      C('\\'), C('Z'),  C('X'),  C('C'),  C('V'),
  C('B'),  C('N'),  C('M'),  NO,      NO,      C('/'),  NO,      NO,
  [0x9C] = '\r',      // KP_Enter
  [0xB5] = C('/'),    // KP_Div
  [0xC8] = KEY_UP,    [0xD0] = KEY_DN,
  [0xC9] = KEY_PGUP,  [0xD1] = KEY_PGDN,
  [0xCB] = KEY_LF,    [0xCD] = KEY_RT,
  [0x97] = KEY_HOME,  [0xCF] = KEY_END,
  [0xD2] = KEY_INS,   [0xD3] = KEY_DEL
};