USB first became available on personal computers circa 1996 when Intel started shipping the new Pentium MMX 200 processors with the new PCI motherboards. The ATX format motherboards provided 2 USB ports which Intel was hoping to replace other older interfaces with. It did not take long before a vast range of new peripherals came to market.
USB had so many advantages. Low cost licensing and cheap to manufacture ensured widespread adoption.
USB cables are designed for longer lengths than are commonly used. USB is designed for a maximum of 5 meters which is over 16 feet. This easily affords the placement of computers and printers as desired.
USB A and B connectors are also designed to be able to be inserted and removed over 1,500 times. The smaller micro USB can handle over 10,000 connect and remove cycles.
In the top left image is the original USB A/B cable logo, The A connector attaches to the computer and B connects to the printer. The USB logo (top left) is often embossed into the plastic sheath. It may also be embossed on the IO shield or printed on the plastic parts of notebooks.
Many devices have integrated cables and only have the USB A connector which connects directly to a computer or hub. Hub may be used when there are not enough available ports. USB supports 127 devices such as powered hubs, keyboards, mice and printers. USB supports 5 tier levels limiting the chaining of hubs.
USB A connectors have been static, but the other end has been more proprietary. Apple used to use a 30-pin connector until the new lightning port was introduced. The micro USB has become more popular with its durable design.
USB supports proprietary firmware which can be a security risk, It’s possible for the NSA etc to make a counterfeit USB stick than can uses to install surveillance code etc. Custom firmware hacks have also focused on injecting malware into devices such as smartphones or USB devices. Your biggest mistake is to assume that the NSA is the only institution abusing this position of trust, they are likely all doing it.
Old notebook machines with the old PCMCIA or PC Card slots can have USB 2.0 cards installed. These make it easy to attach USB flash memory sticks to copy files at high speeds.
More recent notebooks have PCI Express based card slots. Low cost USB 3.0 cards can add more ports to a machine with USB 2.0 ports.
USB add-in cards have been on the market for decades. PCI cards with 4 USB 2.0 ports were popular with Windows 98 Second Edition as they provided more speed and many new USB peripherals were becoming available. These cards remained on the market for many years.
PCI EXPRESS CARD
USB 3.0 increased the speed by 10x and with a new cable and connector, The new connector is backwards compatible but it has additional pins for more signals. USB 3.0 has largely adopted blue plastic parts to show the higher speed option. USB 3.0 cables have more conductors to increase the bandwidth. USB 3.0 PCI Express x1 cards are inexpensive and are popular for upgrading older machines. Models with 5 ports on the bracket and an internal 20-pin front panel port are under $20.00.
Charging cables are designed to use the higher current available with revisions to the USB 3.0 standard (BCC 1.2) which provides over 2A of current.
TYPE C CONNECTOR
USB 3.1 type C ports will likely be side-by-side with USB 2.0 and USB 3.0 ports for several years as the new ports are not plug compatible. Front panel USB boxes are available in wide diversity for every requirement.
USB type C are reversible which will make them more durable. USB Type-C devices also support power currents of 1.5 A and 3.0 A over the 5 V power bus in addition to baseline 900 mA; devices can either negotiate increased USB current through the configuration line, or they can support the full Power Delivery specification using both BMC-coded configuration line and legacy BFSK-coded VBUS line. PCI Express cards with USB 3.1 type C ports are now becoming widely available.
In more recent years mobile phones have started to use USB connectors, The traditional B connector has been replaced with a mini USB connector. Most recently the smaller micro USB has been popular as mobile devices become thinner. Non-obviously, the micro format is the most durable from the point of designed insertion lifetime. The standard and mini connectors were designed for less frequently than daily connections, with a design lifetime of 1,500 insertion-removal cycles
USB cable quality has been all over the dial. Cheap cables did not last long and connectors crumbled easily. Eventually better materials resolved the problems. More recently cable thickness has become larger as more devices use the 5V supply for charging.
BCS 1.2 is a standard for higher current from USB ports. Mobile phones and hard disks need extra power. USB 2.0 and USB 3.0 ports are both included in the standard.
An added advantage of BCS 1.2 are its provisions to charge dead or weak batteries. Batteries below the “weak battery threshold” are allowed to charge with a current higher than the 2.5mA suspend current, regardless of the port type. Once the battery reaches a nominal level, the device is mandated to enumerate within a certain timeframe to maintain a higher current draw from USB ports that require enumeration.