Extended keyboard

Hello Alexandr! 27 Jan 02 00:53, Alexandr Khavzin -> All: AK> Tell me how to make extended keys (EXT, cursor, etc.). AK> That is. one contact closes, and a signal from 2 buttons goes to the computer. Hy... As one of the options, you can try this: ╒═════════════════════════ Start 123.txt ═════════════════════════╕ ┌──┐ ┌───┐ xA1 ──┤1 o────┤ & o────── xK1 └──┘ ┌──┤ │ │ └───┘ Key ───────┤ ┌───┐ ┌──┐ └──┤ & o────── xK2 xA2 ──┤1 o────┤ │ └──┘ └───┘ ╘═════════════════════════ End 123.txt ═════════════════════════╛ For _each_ extended button you assemble a circuit like this. Two inverters (any) and two 2I-HE elements with an open collector! Type 155LA8 - you get one housing per button ;) Now what do you connect where - “Key” is your own button. "0" - the button is not pressed, "1" - the button is pressed. xA0/xA1 are connected to the address bus (to the bits for the desired buttons) Hy or not on SHA, but to the tires in the keyboard itself xK1/xK2 are connected to the data input from the keyboard. Hy for EXT the scheme will be like this: xA1 == A8 xK1 == KL0 xA2 == A15 xK2 == KL1 Hy and so on... However, you can also reduce the number of elements - since all extended keys are pressed together with CS, then you don’t have to set each time the elements of "clicking" CS, and put one common... Alexand