Program to calls to echo the typed characters, C/C++ Programming

Assignment Help:

Write a main program that uses these system calls to echo the typed characters. The pseudo code will look something like:

void traphandler ()  {

   if (R0 == 0) { // read system call

      R1 = getchar(); // poll the status register of the IO terminal until a char is available then load it into R1

   } else if (R0 == 1) { // write system call

      putchar(R1); // just store R1 to memory location 0xfff0

   }

   enableInterrupts();

}

void main() {

   char c;

   while (1) {

      c = read();  // set R0 to 0 can issue the 'trap' instruction, result will be in R1

      write(c);  // set R0 to 1 and set R1 to 'c' and issue the 'trap' instruction

   }

}


Related Discussions:- Program to calls to echo the typed characters

The Shell or Command Line Interpreter is the fundamental Use, 1. The shell ...

1. The shell must support the following internal commands: i. cd - Change the current default directory to . If the argument is not present, report the current directory. If t

Should i call a destructor explicitly on a local variable?, Should I call a...

Should I call a destructor explicitly on a local variable?

Lowest cost entry, code for solving optimal solution for matrix

code for solving optimal solution for matrix

Odd even program, Write a program called OddEven that will prompt the user ...

Write a program called OddEven that will prompt the user for an integer and print/display a message indicating whether it is even or odd. Continue prompting for numbers from the us

Should one design a classes from the outside, Should one design a classes f...

Should one design a classes from the outside (interfaces first) or inside (data first)? A: From the outside. A superior interface provides a simplified view which is express

Define automatic storage classes - computer programming, Define Automatic s...

Define Automatic storage classes - computer programming? The Variables declared within function bodies are automatic by default and automatic variables are declared inside a fu

Explain concept of object initialization, Object Initialization An obje...

Object Initialization An object of a derived class can be initialized to an object of a base class. If both the classes have similar data members, then no specific constructor

Program is to find the area of room, Program is to find the area of room: ...

Program is to find the area of room: Program is to find the area of room with default values using classes & object class room   {   private:     int len;     i

Write a program that reads data from array, Write a program that reads data...

Write a program that reads data into an array of type int. You must use an array. The numbers input are attendance numbers at a conference. Keep a running average, number of events

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd