What is PS2 cable?
The PS/2 interface is an interface on a PC-compatible computer system that can be used to link a keyboard and mouse.
The PS/2 cable is used to connect the keyboard (with 6 pin mini din connector) to a computer.
What kinds of keyboard interfaces are there?
1.PS/2 interface; first appeared on IBM's PS/2 machine, hence the name. This is a special interface for mouse and keyboard, it is a 6-pin circular interface, but the keyboard only uses 4 pins of which to transmit data and power supply, and the remaining 2 are empty pins;
2. USB interface; the full name of USB is Universal Serial Bus, USB supports hot swap, the advantages of plug and play, so the USB interface has become the most important interface method for various devices. USB has three specifications, namely USB1.1 and USB2.0 and the emerging USB3.0...
3. MIDI interface; MIDI interface is a kind of hardware connected between a computer and a MIDI device, and it is also a standard for digital music.
The difference between the keyboard interface ps2 and usb type
To put it simply: a data packet of a USB keyboard is only 8 bytes (why only 8, this is because the protocol stipulates, why the protocol stipulates this, because the USB speed was slow in the early days, using interrupts to transmit a maximum of 8 packets) bytes), of which 2 bytes mark the status, and the remaining 6 bytes are used to record the scan code of the currently pressed or bounced button, so the USB keyboard can describe the status of 6 buttons at the same time.
PS/2 keyboard does not use this specification. PS/2 is: report whatever is pressed, and report whatever is bounced. If 10 keys are pressed at the same time, 10 pressing events will be reported in turn. The state of how many keys are recorded at the same time, there is no limit to the protocol, and it depends on the operating system itself, so the PS/2 keyboard can theoretically achieve unlimited keystrokes without collision.
