Programming 101–3. ones and zeros
Disclaimer: the Programming 101 series was originally written to be published as a short book. However, since I never got round to finishing it, I’m publishing the chapters here as individual blog posts…
Ones and zeros
Now that we have a theoretical understanding of what a computer and a
program is, we can take a more practical standpoint and look at how
computers and programs are actually implemented.
Bits and bytes
A computer is an electronic device, which really only “understands” on
and off — two states that are manifested by differences in voltage. Think of how the light goes on and off when you flip the switch. In a way, a computer is basically a giant collection of light switches.
This is why a computer’s brain, so to say, its CPU or “central processing unit”, can only operate on 0 (off) and 1 (on), or bits. These can be combined to represent binary numbers, e.g. 100 = 4. This binary stream is how we feed a computer both instructions and data. In it’s binary, most basic form, this is called “machine code”.
It makes sense to group bits into units; otherwise, we would just end up
with one long string of ones and zeros and no way to chop it up into
meaningful…
