C Program to Display SCAN and ASCII Codes of Keys on Keyboard Using 8086 Interrupt

Output (ASCII and SCAN code) when a is pressed

This program displays SCAN code and ASCII code of any key pressed on the keyboard. We use inregs is made zero in the program. Then interrupt 16h is called using int86() function in dos.h. The arguments are interrupt number (in hexadecimal ; in C 0x16) pointer to input register and pointer to output register.
The interrupt stores scan code in higher byte of accumulator and ASCII code in lower byte of accumulator.

8086 interrupt number 16h (hexadecimal) to read a keystroke from keyboard. The condition for this interrupt is that the higher byte of accumulator (AH) should be 00h.

#include<stdio.h>
#include<dos.h>
#include<conio.h>
void main()
 {
 union REGS inregs,outregs; //declaring 2 register files
 clrscr();
 inregs.h.ah=0x0; //pre-requisite for desired operation of interrupt 16h
 int86(0x16,&inregs,&outregs); //calling interrupt 16h
 printf("\nScan Code :%d\nASCII code:%d\n",outregs.h.ah,outregs.h.al);
 getch();
 }