The keyboard built into a laptop seems uncomfortable to many. When they come home, they connect an external keyboard to it. Using two keyboards with a desktop computer can also be useful in a number of situations.
Instructions
Step 1
If you are going to connect a second keyboard to the USB interface, first try looking for a PS / 2 keyboard emulation feature in the CMOS Setup utility. Otherwise, the second keyboard you connected will not work in DOS and Windows 95 and Linux with kernel up to 2.2 inclusive, and in Windows 98 it will work only with drivers. In Linux with kernel 2.4 inclusive, as well as Windows XP, Vista and 7, the second keyboard will work regardless of whether PS / 2 emulation mode is enabled in the BIOS, however, entering CMOS Setup from a USB keyboard may not be possible. Also, the GRUB bootloader may not respond to pressing keys on a USB keyboard even in emulation mode.
Step 2
A laptop usually has only one PS / 2 connector, and it is free, unless a mouse is connected to it. In the CMOS Setup utility, you can choose which interface will be displayed on this connector - for the keyboard or for the mouse. If you are using a PS / 2 mouse, connect the keyboard via USB and vice versa. Correctly select the PS / 2 interface mode in CMOS Setup.
Step 3
If the first keyboard is connected to the computer via the USB interface, connect the second one either through another same connector, or through the PS / 2 connector, depending on which interface it is equipped with.
Step 4
The number of keyboards that can be used with USB connectors in a computer is limited only by the interface's power supply capacity, as well as by the number of connectors. A modern keyboard draws a current of about 20 mA, which is relatively low. Remember, however, that if you do not leave free connectors, you will not be able to connect flash drives to the computer, unless you disconnect one of the keyboards first.
Step 5
You can press combinations of several keys both from one keyboard, or from any two at once. For example, try to copy text to the clipboard by pressing "Control" on one keyboard and "C" on the other. Similarly, you can press and simultaneously on three keys using one, two or three keyboards in any combination.
