/*
 * Program: Global Communicator II - scanner signals converter
 * Programmer: Robert John Morton UK-YE572246C
 * Date:  Tue 22 Sep 2020

From the directory in which conv.c resides: 
to compile: gcc volmet.c -o volmet */

#include <stdio.h>   // input output to/from the console and keyboard
#include <stdlib.h>  // standard functions for the 'C' language

int VM[7][2] = {  // frequency & signal strength 0-120
  {  3413, 100 },
  {  4742,  50 },
  {  5450,  70 },
  {  5505,  36 },
  {  8957,  44 },
  { 11253,  19 },
  { 13264,  27 }
};
int S[8];

void main() {
  FILE *HS = fopen("scope.dat","rb+");  // open the output file for writing
  int q = 0;
  for(int i = 0; i < 7; i++) {           // for byte of the input file

    fseek(HS,VM[i][0] - 4,SEEK_SET);  // lower sideband freq

    int q = VM[i][1];                    // get signal strength
    for(int j = 0; j < 4; j++) {         // compute sideband amplitudes
      S[j] = q;
      q *= 0.707;
    }
    fputc(S[3],HS);
    fputc(S[2],HS);
    fputc(S[1],HS);
    fputc(S[0],HS);
    fputc(q,HS);
    fputc(S[0],HS);
    fputc(S[1],HS);
    fputc(S[2],HS);
    fputc(S[3],HS);
  }
  fclose(HS);                 // close the output file
}