Your Computer Memory is a Lie

When you first learn to program, memory seems pretty straightforward. You have a bunch of bytes, each with an address. If you want to read or write something, you specify ….

If you want to read or write something, you specify the address, and the computer goes to that place and does your bidding. Sure, some addresses might be reserved for hardware or the operating system, but the general idea is simple: memory is a big array of bytes. Just like we pretend that a wire is a perfect conductor, the big array of memory model used to be a slight twisting of the truth.

On a modern computer, however, it is almost entirely a lie. The address you use probably isn’t a physical address. The data you read might not come from RAM at all.