Author Topic: Check Sum  (Read 503 times)

0 Members and 1 Guest are viewing this topic.

Offline goodolddays

  • Trade Count: (0)
  • ******
  • Forum Posts:
  • Riverstone NSW
Re: Check Sum
« on: February 26, 2012, 07:43:48 PM »
http://en.wikipedia.org/wiki/Checksum

A checksum is basically a mathmatical representation of the file prior to copying.  It is a known value and checks it after copying to ensure it is valid.

Basically the same as a MD5 hash for a file on your computer (virus programs use these all the time).

For example - run.exe (made up file - is hashed and it has a known static value).  If one part of the code is modified or even a space added, the hash will have changed and wont match
That would make sence, however I read a new rom and it gave me a checksum but then i read the same rom without touching it and the checksum had changed, it just keeps changing!

I can't really remember but I think that is normal
I need more room ! and more $$$