There was a time when all PCs had at least one serial and one parallel port. Today, you won’t find either of these ports on a typical desktop or laptop computer, but just because consumer-facing technology has left the serial port behind, doesn’t mean it’s anywhere close to dead.
Serial ports are older than most of modern computing—and still kicking
Some ideas are too good to die
The serial port is more precisely referred to as the RS-232 and back in the day as the COM port. While the first IBM PC came out in 1981, serial ports are actually from the ’60s. This interface was designed to connect teletype machines.
When those early PCs arrived, adopting the mature and well-supported serial connection was a no-brainer and it was used for all sorts of things, such as connecting modems and mice. The 9-pin (DB9) connector is the most familiar, but there was also a 25-pin variant which might look like a parallel port at first glance.
Before we had network cards in our home computers, my friends and I would play multiplayer games using a special null modem cable that connected the two serial ports of our PCs together. This was more than fast enough for a basic two-player deathmatch. A more boring use for this was direct PC-to-PC file transfers.
What “Serial” actually means (and why USB didn’t replace the idea)
Marching in a row
The word “serial” gets thrown around a lot, but all it means is that you’re moving data one bit at a time over a single channel. That might sound like a step backwards from a parallel connection that can send multiple bits at a time, but it turns out serial communications has many practical advantages.
You need fewer wires to send serial information, the cables can be longer, and the chances that timing issues will crop up are much smaller.
Quiz
USB standards & connectors
Trivia Challenge
From clunky Type-A plugs to lightning-fast USB4 — test your knowledge of the universal serial bus revolution.
HistoryConnectorsSpeedsStandardsHardware
In what year was the original USB 1.0 specification officially released?
Correct! USB 1.0 was released in January 1996 by a consortium led by Intel, Compaq, Microsoft, and others. It aimed to replace the chaotic mix of serial ports, parallel ports, and PS/2 connectors that plagued early PCs.
Not quite — USB 1.0 launched in January 1996. It was developed by a consortium including Intel and Microsoft to simplify the frustrating tangle of legacy ports on personal computers at the time.
What is the maximum data transfer rate of USB 2.0, also known as ‘Hi-Speed’ USB?
Correct! USB 2.0 tops out at 480 Mbps, which is why it earned the ‘Hi-Speed’ label when it launched in 2000. That was a massive leap over USB 1.1’s 12 Mbps Full Speed ceiling, making it practical for external hard drives and cameras.
Not quite — the correct answer is 480 Mbps. USB 2.0 is branded ‘Hi-Speed’ and launched in 2000, offering a 40x improvement over USB 1.1’s Full Speed 12 Mbps mode, which made external storage far more viable.
Which USB connector type was specifically designed for use with mobile phones and cameras, featuring a distinctive 5-pin trapezoidal shape?
Correct! USB Mini-B was the go-to connector for early digital cameras and mobile phones before being largely replaced. It features a recognizable five-pin trapezoidal design and was formally specified in USB 2.0, though it has since been superseded by Micro-B and USB-C.
The correct answer is USB Mini-B. It was the standard connector for early digital cameras and many mobile phones, featuring a 5-pin trapezoidal shape. It was eventually displaced by the slimmer Micro-B connector, which allowed for thinner device designs.
USB 3.0 was later rebranded by the USB Implementers Forum. What is its current official name?
Correct! The USB-IF rebranded USB 3.0 as USB 3.2 Gen 1 to fit into a unified naming scheme. It still delivers the same 5 Gbps ‘SuperSpeed’ transfer rate — the confusing renaming was meant to streamline the standard’s versioning but arguably made it more complicated.
Not quite — USB 3.0 is now officially called USB 3.2 Gen 1. The USB Implementers Forum rebranded the entire USB 3.x family to create a unified naming structure, though the 5 Gbps SuperSpeed performance of the original USB 3.0 remains unchanged.
What key physical feature makes USB Type-C different from all previous USB connector types?
Correct! USB Type-C’s most celebrated feature is its symmetrical, reversible design — you can plug it in either way without fumbling. Introduced in 2014, it also supports far higher power delivery and data speeds than older connectors, making it a true universal solution.
The standout feature is its fully reversible design — you can insert a USB-C plug either way up, ending the frustration of guessing the correct orientation. Introduced in 2014, USB-C also supports higher power delivery and data speeds than its predecessors.
Which organization is responsible for developing and publishing the USB specification?
Correct! The USB Implementers Forum (USB-IF) is the non-profit organization formed by the original USB developers to maintain and promote the USB specification. Founded in 1995, it certifies compliant products and grants the right to use the official USB logo.
The correct answer is the USB-IF, or USB Implementers Forum. This non-profit was founded in 1995 by the companies that originally developed USB, including Intel and Microsoft. It maintains the specification, runs compliance programs, and certifies products to carry the USB logo.
What maximum power output did USB Power Delivery 3.1 introduce, enabling charging of high-performance laptops?
Correct! USB Power Delivery 3.1, released in 2021, dramatically raised the ceiling to 240 watts using Extended Power Range (EPR) mode. This is enough to charge even power-hungry gaming laptops and workstations over a single USB-C cable, replacing bulky proprietary chargers.
The answer is 240 watts. USB Power Delivery 3.1, introduced in 2021, added an Extended Power Range (EPR) mode that maxes out at 240W over a USB-C cable. Earlier PD versions were capped at 100W, which was insufficient for many high-performance laptops.
USB4, released in 2019, is based on which company’s proprietary technology that was donated to the USB-IF?
Correct! Intel donated the Thunderbolt 3 specification to the USB-IF, which became the foundation for USB4. This means USB4 at its fastest tier (40 Gbps) is technically compatible with Thunderbolt 3 devices, blurring the line between the two standards significantly.
The correct answer is Intel’s Thunderbolt 3. Intel donated its Thunderbolt 3 spec to the USB Implementers Forum, and it became the basis for USB4. The top USB4 speed tier of 40 Gbps mirrors Thunderbolt 3, and the two standards share a high degree of compatibility.
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Today we use USB for almost every type of device connected to our PCs, and the “S” in USB is for “serial.” So even our most advanced and fastest data connection technology today still shares the same core concept for data transmission.
The same goes for SATA (Serial-ATA) and PCI Express. They are all examples of high-speed serial connections. What changed wasn’t the concept, but the implementation. Modern standards layer complex protocols, error correction, and high-speed signaling on top of the same fundamental idea.
What makes RS-232 different is how raw and simple it is. There’s basically no abstraction going on, which is exactly why it hasn’t disappeared and is still incredibly useful.
RS-232 refuses to die in industry and engineering
The language of machines
In Star Wars: A New Hope the shiny and effete droid C-3PO is asked whether it can operate the “vaporaters” moisture farmers use on the desert planet of Tatooine, to which it replies: “Vaporators! Sir, my first job was programming binary load lifters, very similar to your vaporators in most respects.”
This has always reminded me of serial port communication, because if you look at industrial machines, medical equipment, lab gear, and even the point-of-sale systems that are in millions of stores across the world, you’re going to see RS-232 ports.
It’s simple, reliable, and you can often reverse engineer an old machine’s serial port communication when all the manuals are lost. At least, so I’ve heard, it’s not like I’d be smart enough to figure it out! Since there are no drivers or dependence on a specific operating system, serial communication really is a fundamental communication method for our machines, and it’s unlikely to ever go away.
- Brand
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OIKWAN
- Cable Type
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USB-C
A USB-C to RS-232 cable adapter that alllows a modern PC to communicate with older hardware or industrial systems.
The deep magics persist
While your laptop or PC may not have shipped with a serial port, and your motherboard probably has nowhere to connect an old-school serial port header, you better believe that modern operating systems still support RS-232. Sometimes it’s necessary to emulate a virtual COM port, and if you connect a USB to RS-232 cable to a modern PC it will have no trouble talking to any device using a serial port, assuming it knows what to say!
Serial ports won’t go away anytime soon
As long as we have industrial systems and other infrastructure that relies on the simplicity, reliability, and durability of the humble serial port either as a primary or fallback communication system, these connectors will be around for the foreseeable future. I wouldn’t be surprised if RS-232 outlives the many connection standards that came after it, ending up as the crocodile of ports. Still perfectly fit for purpose after all this time.
Stephan is the sports journalist for the Maple Grove Report.
