Slashdot Mirror
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?
What have you replaced with USB?
Keyboard and mouse.
Scanner, though I didn't have a scanner prior to getting USB.
USB flash drives, though I rarely use those. They mainly replaced floppys or zip disks.
I went from SCSI to firewire to eSATA. USB for storage has always been considered a fallback.
Network printers have become so cheap that using one for just two computers is reasonable. At least that was my thinking for getting one at home.
I use a bunch of USB devices not mentioned here, but they didn't exist prior to the introduction of USB, which mean they never existed in a non-USB version and USB never replaced the interface. It's more like USB greatly expanded the available devices you can connect your computer to. If you asked what I have connected to the computer, which you didn't have prior to getting USB, then the answer would be totally different.
like usb3?
A MAX232 chip converts the +5V/0V of a uart (let's assume we're running at 5V) to the RS232 standard signal (-12V/+12V or thereabouts). In other words, it converts RS232 to TTL and back. A FT232 takes the TTL coming from a UART and presents itself to the system as a virtual USB serial port (it is thus a USB to UART converter).
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.
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.
Windows 7 still does it.