What USB Has Replaced (And What it Hasn't) (arstechnica.co.uk)

An anonymous reader writes with a story at Ars Technica about the evolution thus far of USB as an enabling technology: Like all technology, USB has evolved over time. Despite being a 'Universal' Serial Bus, in its 18-or-so years on the market it has spawned multiple versions with different connection speeds and many, many types of cables. A casual search around the shelves by my desk shows that I've got at least 12 varieties, and that's not even counting serial and PS/2 adapters. What have you replaced with USB?

Comments

Not replaced: serial and parallel ports.

[Anonymous Coward]

1. Serial ports, because you don't need a complex microcontroller and driver stack just to throw a few bytes between two machines.

2. Parallel ports, because sometimes you want some basic high/low monitoring on a few lines and you don't want some ridiculous custom peripheral just to do this.

Re:Not replaced: serial and parallel ports.

[Opportunist]

Yup, pretty much this.

It's trivial to implement a serial connection in a microcontroller. All you need is a level shifter like the dime-for-dozen MAX232 and you're set. For USB, this requires a lot more implementation overhead (not to mention getting a genuine UID if you want to ship it), and literally EVERYONE who has ever even dabbled in microcontroller programming knows how to deal with a MAX232. Pushing information down the serial line is like the Hello World of microcontroller tinkering.

That's why you can still get PCI-E serial controller rather cheaply. And, lo and behold, almost all of them contain some variant of the MAX232.

Re:Not replaced: serial and parallel ports.

[AC-x]

My motherboard doesn't even have serial or parallel ports you insensitive clod!
 
... I suppose I could use one of these...

Re:Not replaced: serial and parallel ports.

[dotancohen]

1. Serial ports, because you don't need a complex microcontroller and driver stack just to throw a few bytes between two machines.

The poster seems to not understand what the words "universal" and "bus" mean in "Universal Serial Bus". He has 12 different varieties of physical connectors, but they all use (different compatible versions of) that same bus protocol, so he can simply use an adapter to interconnect between them. His PS/2 "adapter" is unreliable, does not completely support either the PS/2 or USB protocols, and will not work with many high-draw PS/2 HID devices, such as the PS/2 Model M keyboards (Lexmark, then Unicomp). Rather, there is a 'standard' mapping of PS/2 connectors to USB that most USB controllers support, but that is a USB feature.

Re:Not replaced: serial and parallel ports.

[_merlin]

Serial ports are definitely still alive and well as a connection of last resort. All my network switches, rack mount servers etc. have a serial console port to help when you can't use the usual network administration interface. Professional desktops also tend to have serial ports allowing you to do initial setup of one of these devices without the need for a USB to serial adaptor.

Centronics-style parallel printer ports, on the other hand, really do seem to have disappeared. You'd be hard pressed to find a computer that includes one any more. They were always a bit troublesome, without good two-way speed negotiation, and with generally unreliable daisy-chaining of peripherals. Requiring thick cables and using unbalanced signals also contributed to poor reliability at higher speeds. It was nice for hobby projects to be able to get logic levels straight out of the connector, but they weren't the best interface for anything else.

Re:Not replaced: serial and parallel ports.

[ZorinLynx]

Centronics parallel ports are something that I do not miss. Even slightly.

Before the USB era, pretty much every peripheral that needed a faster connection than serial but was too cheap to implement SCSI used a parallel port. Webcams (Connectix QuickCam was a famous one), Zip drives, laplink cables, etc... it was insane. Parallel ports provided no power, so these devices either required a power brick or stole power from the AT/PS2 keyboard interface.

When it worked, great! When it didn't, good luck getting it working. I always used to pay a little more for SCSI when it was available because it was faster and a million times more reliable.

Remember the Zip Drive Plus? It was a drive that could either do SCSI or Parallel on the same port. I like to think of it as the height of the clunky, kludge-filled world we had before USB.

If the personal computer market ever had a "savior", it would be USB. It was truly a dark time before that.

Pretty much everything

[Todd Knarr]

USB's been the connector of choice for most of my peripherals. It replaced the floppy drive connector for portable media. It replaced dedicated connectors for keyboards, mice, tablets and the like. My headsets are almost always USB, whether they're wired or wireless. Webcams. The only things I don't use it for are primary networking (hardwired Ethernet there), non-portable mass storage (hard drives and optical drives), and video. Sometimes I still use the PS/2 keyboard connector for non-Windows UEFI systems where a USB keyboard won't get initialized during POST. It's fast enough, there's typically more than enough connectors (especially with a hub for non-latency-sensitive devices), and it's almost universally present and usable.

Re: Pretty much everything

[mark-t]

I have this terrible feeling that I'm probably going to regret asking this, but why do you need to press 10 keys at once?

Re: Pretty much everything

[Maxwell'sSilverLART]

I have this terrible feeling that I'm probably going to regret asking this, but why do you need to press 10 keys at once?

In a word: EMACS.

Re:Displays

[Noah Haders]

like usb3?

USB created a whole category of products.

[140Mandak262Jamuna]

No one ever figured out the right way to power a little fan attached to the chop sticks to cool your noodles as you pull them from the bowl, till USB came along. And there were some twenty more such crazy things powered by USB.

USB is a support nightmare

[fyngyrz]

Unlike ethernet, which is pretty much standard from platform to platform and basically trivial to support, USB code is completely different between linux, OS X, and Windows, and is a mess, API-wise.

I write software defined radio stuff, and after one incredible nightmare getting a USB SDR to work on all three platforms using conditional compilation (I did succeed), I swore off. No more. If it doesn't have an ethernet interface, or a USB-to-ethernet server app compatible with the standard SDR protocols that makes it appear to me as an ethernet SDR, it's not happening.

Luckily, some of the best SDR manufacturers out there have done it right. Andrus, AFDRI, and RFSPACE. And there are some servers that have been built to hide the abortion of USB, but so far they are very much platform-specific, for the very reason I described above.

USB. Ugh.

Re:USB is a support nightmare

[Anonymous Coward]

All you have to do is create yet another API, and use it to write shims for the other three!

Seriously, though, the way Windows handles USB is so amazingly stupid. Unplug a mouse from one port and plug in into a different port. I'm not even talking about some special custom type of device that needs proprietary drivers, just a generic HID mouse. It will then spend about 30 seconds "installing" the drivers for that other port. And good luck if you take a hub full of devices and plug that into a different port.

Re:USB is a support nightmare

[KingMotley]

This doesn't happen if your USB device properly supports USB serial numbers. The problem only exists if windows has to generate a semi-unique serial number for the device because it decided not to implement it.