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

#title, Given an integer n and a permutation of numbers 1, 2 ... , n-1, n w...

Given an integer n and a permutation of numbers 1, 2 ... , n-1, n write a program to print the permutation that lexicographically precedes the given input permutation. If the given

Masm procedure to perform letter case conversion, Assignment:  write a C pr...

Assignment:  write a C program and a MASM procedure.  The C program calls the MASM procedure to perform letter case conversion. Text sections covered:  12.1 to 12.3.1 Write a

Computer Science Engineering C++ Homework, Temperature Conversions. Problem...

Temperature Conversions. Problems 28 through30generate temperature-conversion tables. Use the following equations that give relationships between temperatures in degrees Fahrenheit

What is the reward of operator overloading?, A: you can exploit by overload...

A: you can exploit by overloading standard operators on a class, the intuition of the users of that class. This allow users program in the language of the problem domain instead of

C program for string operations, Aim: To implement a program for following...

Aim: To implement a program for following string operations: Length of String. String Concatenation. Substring (provide start index and length) Find character a

Array, array itself is a pinter.explain

array itself is a pinter.explain

Write a c program to input five numbers, Write a C program to input five nu...

Write a C program to input five numbers and print them out on a new line e.g 5, 10, 15, 20, 25 displayed as   5   10   15   20   25 #include stdio.h   void main()   {

Define some important point for bit fields with structures, Define some Imp...

Define some Important Point for bit fields with structures? Only n lower bits will be assigned to an n bit number thus type cannot take values larger than 15 (4 bits long)

C program for string address, C Program for STRING ADDRESS #include std...

C Program for STRING ADDRESS #include stdio.h> #include conio.h> #include string.h> void main() {           char *name;           int length;           cha

Minimum shelf, how to find minimum number if shelves required

how to find minimum number if shelves required

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