Question

Translate the following C program to Pep/9 assembly language:

#include <stdio.h>

char toLower(char ch)
{
if (ch >= 'A' && ch <= 'Z' )
       ch += 'a' - 'A';
return ch;
}

int main()
{
char ch, conversion;
printf("Enter an uppercase letter: ");
scanf("%c", &ch);
conversion = toLower(ch);
printf("\nLetter after conversion: %c\n\n", conversion);
return 0;
}

Answer 1

This is how to convert lower case letters to upper and vice-versa:
Code: In assembly language
.MODEL SMALL
        .DATA
                MSG  DB  0DH,0AH, \\ ENTER THE STRING :-----> :  $\'
                MSG2 DB  0DH,0AH, \' YOUR STRING IS  :-----> :  $\'
                STR1 DB  255 DUP(?)
                ONE  DB ?
                TWO  DB ?
          .CODE
BEGIN:
          MOV AX,@DATA
          MOV DS,AX
          LEA DX,MSG
          MOV AH,09H
          INT 21H
          LEA SI,STR1
          MOV AH,01H
READ:
          INT 21H
          MOV BL,AL
          CMP AL,0DH
          JE  DISPLAY
          XOR AL,20H
          MOV [SI],AL
          INC SI
          ;CMP BL,0DH
          JMP READ
DISPLAY:
          MOV AL,\'$\'
          MOV [SI],AL
          LEA DX,MSG2
          MOV AH,09H
          INT 21H
          LEA DX,STR1
          MOV AH,09H
          INT 21H
         ; MOV AH,4CH
         ; INT 21H
          .EXIT
END BEGIN