One of the most complex-looking parts of a computer’s internals is its “motherboard”.
Ironically, while motherboards often look intimidating, they’re one of the least complex parts of a computer. In effect, they’re simply a “printed circuit board” (PCB) with “ports” for a CPU, onboard memory (as RAM), an input (typically for at least a keyboard or other computer data), and an output (typically via a screen). In most typical computers, there are other built-in features, including long-term storage (as a hard drive), a graphics card port, and network ports (including wireless).
Without a motherboard, everything in a computer would be a gigantic tangle of wires. So, while the motherboard isn’t particularly complex, it’s critical to keep everything organized and regulate airflow for heat management.
Failing
Typically, the extreme complexity of a motherboard means it’s the first thing to fail.
Thankfully, it’s also often one of the least expensive parts of a computer.
Clock
Beyond keeping everything organized, motherboards tend to come with a built-in “clock” that oscillates a 0-1-0-1 signal. It’s a bit like a ticking clock, with each 1 as a cycle. All the sequential logic circuits get this signal, and the clock runs at about 200,000,000 times a second (200 MHz).
The clock is typically made of quartz, since quartz resonates at a predictable vibration when electricity runs through it. However, heat can modulate those vibrations, and the inaccuracies from that heat can resonate for upwards of 30 seconds a month. The easiest solution has been to synchronize the time consistently with a timeserver (NTP protocol).
Designing
To create a computer system, not everything starts with PCBs.
- First, the designer needs to understand what circuits are doing, so they need schematics.
- Then, they will use “breadboards” to create prototypes of electronic circuits, which don’t require soldering and are completely reusable. The circuits will be low-speed because they’re simply clipped onto the board.
- After they know what they’re doing or want something higher-speed, they’ll either use “strip board” to prototype mid-speed circuits or PCBs for high-speed circuits.
- Finally, when they want to build something for commercial use, they’ll use PCBs.
The Gerber format is a convenient alternative to creating something directly on a PCB. It’s an open PCB standard that gives all the instructions necessary for an engineer to manufacture finished computer parts at scale.
The improvements of error-correcting code within processors have made circuit design much more forgiving than in the past.