text: // System call numbers
  #define SYS_fork    1
  #define SYS_exit    2
  #define SYS_wait    3
  #define SYS_pipe    4
  #define SYS_read    5
  #define SYS_kill    6
  #define SYS_exec    7
  #define SYS_fstat   8
  #define SYS_chdir   9
  #define SYS_dup    10
  #define SYS_getpid 11
  #define SYS_sbrk   12
  #define SYS_sleep  13
  #define SYS_uptime 14
  #define SYS_open   15
  #define SYS_write  16
  #define SYS_mknod  17
  #define SYS_unlink 18
  #define SYS_link   19
  #define SYS_mkdir  20
  #define SYS_close  21
  
  // ASSIGNMENT TASK 1
  #define SYS_waitx 22
  #define SYS_ps 23
  #define SYS_set_priority 24
  #define SYS_current_ticks 25