text: #ifndef __DELAY
  #define __DELAY
  
  #include <stdlib.h>
  #include <system_vars.h>
  
  extern void delay(uint8_t period);
  
  #define from_ms(period)         ((int16_t)(1L * (period) * (GET_VDP_FREQUENCY()) / 1000))
  #define get_future_time(period) ((int16_t)(((int16_t)JIFFY) + (period)))
  #define is_time_past(ft)        ((ft - ((int16_t)JIFFY) < 0))
  
  #endif
  