[RESOLVED] One little glitch

[Barry201]

Hi, I am new to this forum and needing some help from the gurus. I am sure this will be an easy one. I am studying assembly for the first time and I need some help with an assignment, which is working fine except for 1 thing. This assignment has a main program and a subprogram. The main is TestYes and the subprog is YesNo. The problem is when the user enters a character other than y/Y or n/N the program goes to "(Y or N)?"... which is GOOD, that's ok so far. But, coming out of that with an n/N directs the program to "Do you want to continue (Y or N)? instead of "Really Stop".
Anyway, like I said, I am pretty green as far as assembly language is concerned and I am probably overwriting alot of code, but that's just where we are in the book/process, so bear with me there, since we have just left learning about jumps and moving on to subprograms now. The codes for each are below. Thanks.

MLB

;;YesNo.asm

INCLUDE PCMAC.INC

.MODEL SMALL
.586
.STACK 100h
.DATA

Prompt1 DB '(Y or N)? $'
Prompt2 DB 13, 10, '$'




.CODE
EXTRN PutDec: Near
PUBLIC YesNo

YesNo PROC
_Begin

_PutStr Prompt1 ;Prompt to enter y or n
_GetCh
mov bl, al
_PutStr Prompt2
cmp bl, 121 ;ascii for 'y'
je ItsaY ;positive for a y/Y
cmp bl, 89
je ItsaY ;positive for a y/Y
cmp bl, 110 ;ascii for 'n'
je ItsaN ;positive for n/N
cmp bl, 78 ;ascii for'N'
je ItsaN ;positive for n/N
call YesNo ;Start over


ItsaY:

mov bx, 1 ;makes bx = 1
ret
ItsaN:

mov bx, 0 ;makes bx = 0
ret


YesNo ENDP
END YesNo


Subprogram....

;;TestYes.asm

INCLUDE PCMAC.INC

.MODEL SMALL
.586
.STACK 100h
.DATA

Prompt1 DB 'Do you want to continue $'
Prompt2 DB 'Really Stop $'
Prompt3 DB 13, 10, 'Done $'
Prompt4 DB 13, 10, '$'


.CODE
EXTRN YesNo : Near
PUBLIC testyes
TestYes PROC
_Begin

_PutStr Prompt1
call YesNo

cmp bx, 0
jne EntryofY
_PutStr Prompt2
_GetCh
mov bl, al
cmp bl, 121 ;equals y
je EntryofN ;done
cmp bl, 89 ;equals y
je EntryofN ;done
_PutStr Prompt4
call TestYes

EntryofY:
call TestYes

EntryofN:
_PutStr Prompt3
jmp Finish

Finish:
_Exit

TestYes ENDP
END TestYes

[minor28]

If you are studying assembly for the first time, why are you using this macro stuff? Why are you studying 16 bit assembly? Go for win32 assembly instead or 64 bit assembly.

OK, I can't really follow your code since I don't know the macros you are using. I have tryed to write it in pure asm code instead. Perhaps you can solve your problem this way.

.model small

assume  cs:cseg, ds:dseg, ss:sseg

; data
dseg segment byte
	Prompt1 db '(Y or N)? $'
	Prompt2 db 13, 10, '$'
	Prompt11 DB 'Do you want to continue $'
	Prompt12 DB 'Really Stop $'
	Prompt13 DB 13, 10, 'Done $'
	Prompt14 DB 13, 10, '$'
dseg ends

; stack
sseg segment stack
	db      100h    dup(?)
sseg ends

; code
cseg segment

start:

YesNo:
;	_Begin
	
;	_PutStr Prompt1 '(Y or N)? $'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt1
	mov	ah, 09h
	int	21h

;	_GetCh
	mov ah, 01h
	int 21h
	mov bl, al
	
;	_PutStr Prompt2 13, 10, '$'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt2 ;new line
	mov	ah, 09h
	int	21h

	cmp bl, 121 ;ascii for 'y'
	je ItsaY ;positive for a y/Y
	cmp bl, 89
	je ItsaY ;positive for a y/Y
	cmp bl, 110 ;ascii for 'n'
	je ItsaN ;positive for n/N
	cmp bl, 78 ;ascii for'N'
	je ItsaN ;positive for n/N
	
ItsaY:
	mov bx, 1 ;makes bx = 1
	jmp @F
ItsaN:
	mov bx, 0 ;makes bx = 0
@@:

TestYes:
;	_Begin

	cmp bx, 1
	jne EntryofN
;	_PutStr Prompt11 'Do you want to continue $'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt11
	mov	ah, 09h
	int	21h
	jmp YesNo
	
EntryofN:	
;	_PutStr Prompt12 'Really Stop $'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt12
	mov	ah, 09h
	int	21h

;	_PutStr Prompt1 '(Y or N)? $'debu
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt1
	mov	ah, 09h
	int	21h
	
;	_GetCh
	mov ah, 01h
	int 21h
	mov bl, al
	
;	_PutStr Prompt14 13, 10, '$'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt14
	mov	ah, 09h
	int	21h
	
	cmp bl, 121 ;equals Y
	je @F
	cmp bl, 89 ;equals y
	je @F
	jmp YesNo
@@:
;	_PutStr Prompt13 13, 10, 'Done $'
	mov	ax, dseg
	mov	ds, ax
	mov	dx, offset Prompt13
	mov	ah, 09h
	int	21h
    mov ax, 4C00h ;exit to dos
    int 21h
	
;Finish:
;	_Exit
	
cseg ends

end start

[Barry201]

Thanks, I got it to work by adding a dx value pretty much like you did. Cool...


mlb