22. Building An EEPROM Programmer (Part 3).

Ok So does it actually work. YES!

On linux you can check the data in the zx81.rom file by typing:

od -Ax -t x1 zx81.rom

Running the EERPROM Reader in Part 1, I can visually see that they look the same. As a final check I got the ERRPROM Reader to add all the bytes together (OK not the best way to check sum a file but I am not here to write a proper CRC checksum routine for the Arduino just now), and also wrote a C program to do the same on Linux called sum.c:

#include 
main()
{
 int c,sum;
 sum=0;
 while ((c=getchar()) != EOF) {
  sum=sum+c;
 }
 printf("Checksum: %d\n",sum);
}

The final value came back as 855105 for both.

Result!

As a final check, I unplugged the Arduino removing power from the EEPROM in the process. Left it for a few minutes and then plugged that Arduino again restoring power to the EEPROM and reran the EEPROM Reader program. All data preserved and sum still the same.