If I saved 1 byte of data on a USB drive, theoretically, would you be able to take apart the USB drive and point to where the 2nd bit of my single byte is? And if it is 0 or 1?
In: Technology
Depends on the type of memory, but in most cases you would need to test it electrically.
For Nonvolatile memory (that is, memory that stays even without power), the main options are burning it to a disk with a laser or flash memory. Flash is what is used in USB drives and SSD card, and that uses something called a floating gate.
In a normal MOSFET transistor like those found in computer memory, you have the gate, the oxide separating it from the body, and then the source and drain (i.e. the two terminals of a transistor). When you apply a big enough voltage (or low enough, depending on the type of transistor) you effectively connect the two terminals via the oxide. A floating gate is a second layer between the gate and the body, and completely isolated such that it’s floating. When you program it (write to it) you draw charges in/out of that gate, to make it a 1 or a 0. Because it’s almost completely isolated (super high resistance material, but not infinite resistance), the charges stay in place and the device is locked into conducting or non-conducting.
For Random-Access Memory (RAM), normally a pair of NAND or NOR gates are connected together such that each’s output goes into the other as an input. This locks one side to be always 1 (as long as there’s power to the system) and the other side to be always 0, but which side is which can change (they just always have to be opposite each other, and the side you’re reading from doesn’t change). Changing that saved bit is then just a matter of flipping which side is 1 and which is 0, which you can do if you get the capacitances correct.
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