Who said you can't do two things at once, or at least in the same day. With that in mind I started learning assembly.

I took this assembly language routine and converted it to c++ and just wanted to show it off for critiquing. Here is the asm code, then the c++.

note the assembly language routine comes from Jeff Duntemans book Assembly Language Step by Step
Code:
Byte2Str:
     mov DI, AX                        ; Duplicate byte in DI
     and DI, 000FH                   ; Mask out high 12 bits of DI
     mov BX, Digits                   ; Load offset of digits into BX
     mov AH, BYTE [BX+DI]       ; Load digit from lookup table
     mov [SI+1], AH                  ; store digit into string
     xor AH, AH                         ; trick to zero out AH
     mov DI, AX                         ; move byte into DI
     shr DI,4                              ; Shift high nyble of bite to low
     mov AH, BYTE [BX+DI]        ; Load digit from digits table into string
     mov [SI], AH                       ; store digit into string
     ret
The C++ with some adaptation
Code:
// Hex2.cpp : Defines the entry point for the console application.

#include <iostream>
using std::cin;
using std::cout;
using std::endl;

#include <string>
using std::string;

#include <stdlib.h>

string byte_to_hexstring(short int);


int main(int argc, char* argv[])
{
	short int number;
	
	// fetch number must be short int
	cout << "Enter a number [0-255]: ";
	cin >> number;
    cout << endl;
    
	// display hexstring equivalent
	cout << "In hex : " << byte_to_hexstring(number);
	cout << endl;
	
	cin.ignore(1);
	
	system("PAUSE");
	return 0;
}

string byte_to_hexstring(short int decimal)
{
	
	string digits="0123456789abcdef";
	string hexstring="  ";

	int temp_digit=0;
	int mask=15;			        // bit mask to eliminate high order nybl
	temp_digit=decimal & mask;      // eliminate high order hex digit;
	
	hexstring[1]=digits[temp_digit];// use digits as look up table to refrence char 
	
	temp_digit=decimal >> 4;         //move high order nyble first hexdigit to low order position
	hexstring[0]=digits[temp_digit];//first char of string equals highorder nyble of decimal

	return hexstring;
}