#include <reg51.h>
sbit SW = P2^7
sbit MTR = P1^0
void MSDelay(unsigned int value)
void main()
  {
  SW = 1
  MTR = 0
  while(1)
    {
      if(SW == 1)
        {
          MTR = 1
          MSDelay(25)
          MTR = 0
          MSDelay(75)
        }
      else
        {
          MTR = 1
          MSDelay(50)
          MTR = 0
          MSDelay(50)
        }
    }
  }
void MSDelay(unsigned int value)
  {
    unsigned char x, y
    for(x=0
      for(y=0
  }