Size doesn't matter

Gradnpa: "I shot more than 700 photos while I was traveling, and I copied them all onto this Disc-on-Key. How come there are only 49 on it now?"

Father: "Dad, what's the size of your Disc-On-Key?"

Grandpa: "It says here 256. What, that's not enough for 700 photos?!"

[contributed by Olga]