Author: David Bryant, Creative Strategist, Google
‘The future… doesn’t arrive all at once.’
—Sid Mead, futurist, visionary, creator of Bladerunner
Booting up a PC
When we first boot up a PC, we take a step back in time.
The very first instructions that a PC executes when powered up are, in computing terms, ancient history. Called the Instruction Set, they were etched into the modern PC’s chip by its distant ancestor decades ago, like hieroglyphics on a pyramid chamber wall. And like hieroglyphics, they are understood by the very few.
The next step a PC takes is to invoke its Microcode. Microcode is fascinating. When a PC first flips on, it is phenomenally stupid. It has no memory, no instructions to execute and isn’t even aware of what devices it is connected to.
It’s a little like the film Memento. The computer wakes with no memory and a few arcane instructions written onto its hand. These very few instructions tell it how to follow more instructions, and so on until the computer gradually becomes less stupid. It all starts with these microscopically small lines of code invoking the 1978 Instruction Set.
The majority of the Microcode is written by the designers and engineers of the chip. So the PC starts to run code from a chip designed a few years ago, but running an instruction set from a time where Jimmy Carter is one year in, the Berlin wall is yet to come down, no-one has heard of the internet, and MC Hammer is 10 years away from being famous.
Forward to the BIOS
So the modern Microcode tells the PC to load the BIOS. Suddenly we leap forward in time to 2005, in the case of my home PC, to when the BIOS was written.
Invoking the BIOS is a little like putting the PC into a coma state.
The basic things like breathing and heart rate get started but that is all. In other words, there’s power on in the basement but nothing on in the control room. The BIOS also tells the PC where its arms and legs are (or where its keyboard and screen are), and how much memory it has and so on.
Back to DOS
Then the BIOS tells the PC to load DOS. Now we really jump back. Suddenly it’s 1982, I am 12 and Spandau Ballet’s ‘True’ is top of the charts.
Actually DOS was written way back in the seventies and changed very little after about 1995. It’s a quick simple language that allows the PC to load a modern operating system like Windows 7. Hence its original name ‘QDOS’ which stood for ‘Quick and Dirty Operating System.’ That lasted until Bill Gates acquired it for Microsoft, and changed the letter ‘D’ to mean ‘Disk,’ presumably for commercial reasons.
So DOS loads, sets a few environment variables, loads whatever version of Windows, and we’re transported to somewhere in the aughties. It’s taken us 45 seconds to come 30 years. But it’s not over yet.