[The Fifth Horseman]

Solved. I didn't know the char type existed in signed and unsigned forms.
Knowing that, I only needed to add a function converting signed char to unsigned char.

#include <iostream>
#include <fstream>
#include <string>
#include <math.h>
#include <iomanip>
using namespace std;

ifstream::pos_type size;
char * cache;

unsigned char unsign(char in)
     {
      if (in>=0) return in;
      else return in+256;
     }


int readint(unsigned __int64 o=0)
     {
      unsigned int out=0;
     for (int i=0; i<=3; i++)
        { out+=unsign(cache[i+o])*pow(256, i);}
      return out;
     }

main () {
  ifstream infile ("in.scb", ios::in|ios::binary|ios::ate);
  if (infile.is_open())
  {
    size = infile.tellg();
    string brk; brk+=char(0x0D); brk+=char(0x0A);
    cache = new char [size];
    infile.seekg (0, ios::beg);
    infile.read (cache, size);
    infile.close();
    cout << "SCB File read to memory:\n";
    unsigned int version=readint(0), lines=readint(4), bytes=readint(8);   
    cout << setw(4) << setfill('0') << hex 
    << "SCB version " << version << "\n"
    << lines << " lines\n"
    << bytes << " bytes\n";
    ofstream outfile ("out.txt", ios::out|ios::trunc|ios::binary);
    if (outfile.is_open())
    {
    for (int i=0xC, l=0; i<bytes+0xC && l<lines; i++)
     {
      if (cache[i]==0)
       { outfile << brk; l++;}
      else
       { outfile << cache[i];}
     }
     outfile.close();
     cout << "Transcription complete!\n";
     }
    else
    cout << "Unable to open output file!\n";
    delete[] cache;
  }
  else cout << "Unable to open input file\n";
  cout << "\n";
  system("PAUSE");
}