I am using: gcc (Ubuntu 4.9.3-8ubuntu2~14.04) 4.9.3 g++ (Ubuntu 4.9.3-8ubuntu2~1

ID: 3679763 • Letter: I

Question

I am using:

gcc (Ubuntu 4.9.3-8ubuntu2~14.04) 4.9.3
g++ (Ubuntu 4.9.3-8ubuntu2~14.04) 4.9.3

I keep getting the following error:

ch4p5.s:13: error: parser: instruction expected
ch4p5.s:15: error: parser: instruction expected

How do I fix it?

Here is what I have:

%include "macros_windows64.s"

.MODEL SMALL

.STACK 100H

@DATA:
PROMPT_1 db 'Enter the hexadecimal number ( max 4-digit ) : $'
PROMPT_2 db 0DH,0AH,'The equivalent 16-bit binary number is : $'
ILLEGAL db 0DH,0AH,'Illegal hex number. Try again : $'
COUNT db ?

.CODE
.STARTUP

MAIN_PROC:
MOV AX, @DATA ; initialize DS
MOV DS, AX

LEA DX, [PROMPT_1] ; load and display the string PROMPT_1
MOV AH,9
INT 21H

JMP @START ; jump to label @START_2

@START_1: ; jump label
LEA DX, [ILLEGAL] ; load and display the string ILLEGAL
MOV AH, 9
INT 21H

@START: ;
XOR BX,BX ; clear BX
MOV [COUNT],30H ; initialize loop counter

@START_2: ; jump label
MOV AH, 1 ; set input function
INT 21H ; read a character

CMP AL, 0DH ; compare Al with CR
JNE @SKIP ; jump to label @SKIP if AL!=CR

CMP [COUNT],30H ; compare COUNT with 0
JBE @START_1 ; jump to label @START_1 if COUNT<=0
JMP @END ; jump to label @END

@SKIP: ; jump label

CMP AL, "A" ; compare AL with "A"
JB @DECIMAL ; jump to label @DECIMAL if AL<A

CMP AL, "F" ; compare AL with "F"
JA @START_1 ; jump to label @START_1 if AL>F
ADD AL, 09H ; add 9 to AL
JMP @OK ; jump to label @OK

@DECIMAL: ; jump label
CMP AL, 30H ; compare AL with 0
JB @START_1 ; jump to label @START_1 if AL<0

CMP AL, 39H ; compare AL with 9
JA @START_1 ; jump to label @START_1 if AL>9

@OK: ; jump label

INC [COUNT] ; increment the COUNT variable

AND AL, 0FH ; convert the ascii into binary code

MOV CL, 4 ; set CL=4
SHL AL, CL ; shift AL towards left by 4 positions

MOV CX, 4 ; set CX=4

@LOOP_1: ; loop label
SHL AL, 1 ; shift AL towards left by 1 position
RCL BX, 1 ; rotate BX towards left by 1 position
; through carry
LOOP @LOOP_1 ; jump to label @LOOP_1 if CX!=0

CMP [COUNT], 34H ; compare COUNT with 4
JE @END ; jump to label @END if COUNT=4
JMP @START_2 ; jump to label @START_2

@END: ; jump label

LEA DX, [PROMPT_2] ; load and display the string PROMPT_2
MOV AH, 9
INT 21H

MOV CX, 16 ; set CX=16
MOV AH, 2 ; set output function

@LOOP_2: ; loop label
SHL BX, 1 ; shift BX towards left by 1 position
JC @ONE ; jump to label @ONE if CF=1
MOV DL,30H ; set DL=0
JMP @DISPLAY ; jump to label @DISPLAY

@ONE: ; jump label
MOV DL, 31H ; set DL=1

@DISPLAY: ; jump label
INT 21H ; display a character
LOOP @LOOP_2 ; jump to label @LOOP_2 if CX!=0

MOV AH, 4CH ; return control
INT 21H
done:
.EXIT

Explanation / Answer

.MODEL SMALL

.CODE
.STARTUP

MAIN_PROC:
MOV AX, @DATA ; initialize DS

MOV DS, AX

MOV [PROMPT_1], 04H

LEA DX, [PROMPT_1] ; load and display the string PROMPT_1

MOV AH,9
INT 21H