Semaforen in ETX

#include <stdio.h>
#include <setjmp.h>
#include <io6811.h>
#include <etx.h>
#include <lcd.h>
#include <keyb.h>
/* =================== Processen ======================== */
SEMAFOOR *sid;                /* semafoor nummer */
PROCES   *proc1id, *proc2id, *proc3id;
int curpos = 0; /* huidige positie cursor */
monitor void toongetal(int getal, int pos)
{
   static char buf[10];
   char *p;
   if (curpos < pos)
   {
      while (curpos < pos)
      {
       lcd_curs_shr();
       curpos++;
      }
   }
   if (curpos > pos)
   {
      while (curpos > pos)
      {
         lcd_curs_shl();
         curpos--;
      }
   }
   sprintf(buf,&quot;%d &quot;,getal);
   p = buf;
   while (*p != 0)
   {
      lcd_data( *p++ );
      curpos++;
   }
}
/* dit is een proces */
void proc1(void)
{
   T_MSG    msg,i;
   enable_interrupt();
   wait(sid);        /* wacht op semafoor */
   i = 0;
   while (1 == 1)
   {
      etstart(60,0x124);
      msg = receive();
      toongetal(i, 0);
      i++;
   }
}
void proc2(void)
{
   int     i;
   T_MSG    msg;
   enable_interrupt();
   /* initialiseer lcd en laat dan proc1 verder lopen */
   lcd_init();
   signal(sid);
   i = 0;
   while (1 == 1)
   {
      etstart(50,0x123);
      msg = receive();
      toongetal(i, 8);
      i++;
   }
}
void proc3(void)
{
   int     teken, vorigteken;
   T_MSG    msg;
   enable_interrupt();
   /* initialiseer lcd en laat dan proc1 verder lopen */
   keyb_init();
   while (1 == 1)
   {
    etstart(10,0x125);
    msg = receive();
    teken = keyb_lees();
    if (teken != 0 &amp;&amp; vorigteken == 0)
    {
       toongetal(teken, 12);
       if (teken == &apos;0&apos;)
       {
          lcd_disp_shl();
       }
         else if (teken == &apos;4&apos;)
       {
          lcd_disp_shr();
       }
       else if (teken == &apos;f&apos;)
       {
          teken = teken;
       }
    }
    vorigteken = teken;
}
}
/*
*-----------------------------------------------------------
* main - start van het programma
*-----------------------------------------------------------
*/
void main(void)
{
   disable_interrupt();
   etx_init();
   /* nu loopt de task switcher */
   sid = screate(0);
   proc2id = pcreate(proc2,2,"proc 2");
   proc1id = pcreate(proc1,2,"proc 1");
   proc3id = pcreate(proc3,1,"proc 3");
   while (numproc > 1)
   {
      pause();
   }
}