in an interview with NPR, Ajay Bhatt, A co-developer of the USB interface, explains why usb-a is not compatible with both forward and backward inserts. He says the lack of A plug-compatible design for usb-a is largely A matter of cost.

usb-a interface, should be the most common and the most common interface.

this universal interface was born 20 years ago, mainly to facilitate the connection between computers and external devices. After the introduction of the interface was quickly promoted to other devices, providing them with data transmission, power supply functions; At the same time, it also extends a lot of devices with USB port.

although, the appearance of usb-a port brings us A lot of convenience. But in fact, we also found that most of the usb-a interface is not compatible with both forward and backward plug.

if the device is placed in some relatively narrow space, when people are not convenient to judge the positive and negative direction of the interface, to connect the data line to the interface becomes a very troublesome thing. Fortunately, there are now usb-c ports and Lightning ports that can plug in and out, making them easier to use.

in an interview with NPR, Ajay Bhatt, A co-developer of the USB interface, explains why usb-a is not compatible with both forward and backward inserts. He says the lack of A plug-compatible design for usb-a is largely A matter of cost.

according to The Verge, Bhatt made a number of attempts to design this universal interface. He wanted the interface to be compatible with most devices, but also to be simple enough. In an interview with PC World, he used a simple example to illustrate his design intention:

when we made this interface, we wanted it to solve the cable connection problems of the 1990s. In the past, there were so many plugs and connectors that it was very complicated and actually not very convenient for people to use. I was hoping for an interface that would help the average family quickly connect a computer to a printer and be able to print what they needed. As long as it's easy enough for them to connect and not have to call me every time for help, I think it's enough.

indeed, the advent of usb-a provides convenience for many devices to connect. Not only can it be used for simple data transmission and power supply, but devices with built-in processing capabilities can also connect to external storage devices via USB ports and play the contents directly.

For example, many cars now come with a USB port that allows you to simply plug in a USB drive and play songs. Contrast from the previous car to modify their own playback equipment, such a design is indeed quite convenient. However, Bhatt also mentioned the problem with this USB interface in the access, which is the problem between the plug-compatibility design and the cost of the interface:

it is not easy to make the USB interface compatible with both forward and backward inserts. If you want to use this design, you have to embed twice as many wires and circuits in the USB port, and the cost is bound to double.

Bhatt also mentioned that they also considered a circular interface for blind plugging. But also due to the cost of the problem, the final also failed to adopt the circular interface. After all, the main goal of universal interfaces is to popularize them, and if there is not much difference in functionality but more cost, vendors and users will not accept it. So, Bhatt made the right choice here, choosing A less costly and convenient solution for usb-a, and bringing popularity to the interface.

manufacturers are thinking about usb-c as the next universal interface.

and usb-a, compared with usb-a, usb-c port volume is smaller, function integration and performance are higher than usb-a, devices can complete power supply, data transmission, display transmission and other functions through A usb-c port to replace usb-a port is the trend.