From: andyrew1@aol.com (Andyrew1)
Newsgroups: rec.games.programmer
Subject: Re: keyboard routines of FOF
Date: 10 Feb 1995 17:35:03 -0500

Here is a keyboard interrupt i wrote for watcom in protected mode


Some basic definitions of keys

#define KEY_BUFFER          0x60
#define KEY_CONTROL         0x61
#define INT_CONTROL         0x20
#define KEYBOARD_INT        0x09

// make and break codes for the arrow keys

#define MAKE_RIGHT      77
#define MAKE_LEFT       75
#define MAKE_UP         72
#define MAKE_DOWN       80
#define MAKE_A          30
#define MAKE_S          31
#define MAKE_D          32
#define MAKE_W          17
#define MAKE_PLUS       78
#define MAKE_MINUS      74
#define MAKE_B          48
#define MAKE_N          49
#define MAKE_ENTER      28
#define MAKE_P          25
#define MAKE_L          38

#define BREAK_RIGHT     205
#define BREAK_LEFT      203
#define BREAK_UP        200
#define BREAK_DOWN      208
#define BREAK_A         158
#define BREAK_S         159
#define BREAK_D         160
#define BREAK_W         145
#define BREAK_PLUS      206
#define BREAK_MINUS     202
#define BREAK_B         176
#define BREAK_ENTER     156

Im sure you can add others that you might need.


void (__interrupt __far *Old_Isr)();  // holds old keyboard interrupt handler
volatile int kbdtable[256];  // table of key presses low 128 is current
				// high 128 has been
volatile char ct1;           // keyboad interrupt vars
volatile int ct2;

#pragma off (check_stack)
void _interrupt _far pkbd_int()
{
  _enable();
  ct1=inp(KEY_BUFFER);
  ct2=(int)ct1;
  ct1=inp(KEY_CONTROL);
  ct1|=0x82;
  outp(KEY_CONTROL,ct1);
  outp(KEY_CONTROL,ct1&0x7f);
  outp(INT_CONTROL,0x20);
  if(ct2>128) {
    *(kbdtable+(ct2-128))=0;
  } else {
    *(kbdtable+ct2)=1;
    *(kbdtable+(ct2+128))=1;
  }
}
#pragma on (check_stack)

void setbiosisr()
{
  _dos_setvect(KEYBOARD_INT, Old_Isr);
  keyloop=biosloop;  /* just a void function for the loop */
}

void setrawisr()
{
  _dos_setvect(KEYBOARD_INT, pkbd_int);
  memset(kbdtable,(char)0,256);
  keyloop=keycodeloop; /* ibid biosisr */
}

void installlowisr()
{
  Old_Isr = _dos_getvect(KEYBOARD_INT);
  setrawisr();
}

The lower 128 bytes of the keytable should be used to test
if the key is currently pressed. The upper 128 bytes should
be used to check if the key was pressed. The program should
clear the appropriate key after it has answered the fact that
the key was pressed.

An example of checking the table.......

void keycodeloop()
{
  if(*(kbdtable+MAKE_LEFT))  /* these answer the lower 128 bytes and */
    movcamx(-mv);            /* are just used if the key is currently */
  if(*(kbdtable+MAKE_RIGHT)) /* pressed. */
    movcamx(mv);
  if(*(kbdtable+MAKE_UP))
    movcamy(mv);
  if(*(kbdtable+MAKE_DOWN))
    movcamy(-mv);
  if(*(kbdtable+MAKE_PLUS))
    movcamz(mv);
  if(*(kbdtable+MAKE_MINUS))
    movcamz(-mv);
  if(*(kbdtable+MAKE_S))
    rcamx(5);
  if(*(kbdtable+MAKE_W))
    rcamx(-5);
  if(*(kbdtable+(MAKE_ENTER+128))) { /* these answer the upper 128 bytes */
    rotmode=(rotmode+1)%2;           /* and are used if the key was pressed */
    *(kbdtable+(MAKE_ENTER+128))=(char)0; /* any time in the past. They are */
  }                                  /* responsable for clearing the table */
  if(rotmode) {
    if(*(kbdtable+MAKE_A))
      rcamy(5);
    if(*(kbdtable+MAKE_D))
      rcamy(-5);
  } else {
    if(*(kbdtable+MAKE_A))
      rcamz(5);
    if(*(kbdtable+MAKE_D))
      rcamz(-5);
  }
  if(*(kbdtable+(MAKE_B+128))) {
    bt=(bt+1)%3;
    switch(bt) {
      case 0: setnbf();
      break;
      case 1: setbf();
      break;
      case 2: setbfz();
      break;
    }
    *(kbdtable+(MAKE_B+128))=0;
  }
  if(*(kbdtable+(MAKE_N+128))) {
    dt=(dt+1)%2;
    switch(bt) {
      case 0: setnbf();
	break;
      case 1: setbf();
	break;
      case 2: setbfz();
	break;
    }
    *(kbdtable+(MAKE_N+128))=0;
  }
  if(*(kbdtable+(MAKE_L+128))) {
    setbiosisr();
    *(kbdtable+(MAKE_L+128))=(char)0;
  }
  if(*(kbdtable+129))
    ndonekey=0;
  if(*(pos+1)<0)
    *(pos+1)=FABS(*(pos+1));
}


I hope this helps you out....