I am an asp.net developer but at current i need to make a simple assembler login which will ask the user for their username, then password, then confirm password and then output whether the passwords match. In short i am a total newbie to this language and struggling to understand it! Any help or tutorials that would help me to achieve the above would be great, i have been googling for a while and still struggling.
I do have the following code though, but sadly it doesnt work:
Thanks in advance =]
TITLE (comparinvariableshideinput.asm)
; This program reads 2 messages, compares the values and displays a message if they match or do not match
.model large ; specify a large memory model for this program
.stack 4096 ; allocate 4096 bytes to the stack
.386 ; use the 386 processor instruction set
.data ; define data variables used by the program
;DECLARE VARIABLES
msg byte "please enter your team-name" ; msg is of type byte and overflows to 19 bytes
msg2 byte 0dh,0ah,"$" ; msg is of type byte and includes line feed, carr return and terminate
msg3 byte 0dh,0ah
byte 0dh,0ah ; add line feed and carr return
byte "the team name entered was" ; add string as listed
byte 0dh,0ah,"$" ; add line feed and carr return and terminate char
msg6 byte 0dh,0ah
byte 0dh,0ah
byte "the team names entered do not match", "$"
msg8 byte 0dh,0ah
byte 0dh,0ah
byte "the team names entered match", "$"
char byte 00h ; allocate 0 to varable char
counter dw 0 ; delc
teamname1 byte 40 DUP ('$') ; define variable to store teamname1 with $
teamname2 byte 40 DUP ('$') ; define variable to store teamname2 with $
.code
; INITIALISE REGISTERS
main PROC
mov ax,SEG msg ; move the segment number used by msg into ax
mov ds,ax ; copy the segment number (ax) into ds (the data register used to store the segment used by this program)
mov ah,9 ; copy function 9 (display to screen) into the high bits of reg ax
mov dx,OFFSET msg ; copy the offset (within the segment in ds) of msg into dx (as dx req's offset within segment to start reading message)
int 21h ; generate interrupt and display message to the screen
xor cx,cx ; clear register cx
cld ; clear the direction flag
lea di,teamname1 ; load the effective address of teamname1 (segment + offset) into di so that we can write to it
; PROCESS AND TEST USER INPUT
EnterTeamname1:
mov ah,8 ; read a character, which is put in al or lower 8 bits of ax
int 21h
cmp al,1bh ; is the character <ESC>
je Maintenance
cmp al,0dh ; or <RET>
je Maintenance
mov [di],al ; store the character in the 1st 8 bits of the mem loc di is pointing at or start of buffer
inc di ; increment the index register, i.e. point to the next 8 bits to be written
jmp EnterTeamname1 ; loop
Maintenance:
xor cx,cx
cld
lea di,teamname2
; load teamname2
mov ah,9 ; copy function 9 (display to screen) into the high bits of reg ax
mov dx,OFFSET msg ; copy the offset (within the segment in ds) of msg into dx (as dx req's offset within segment to start reading message)
int 21h ; generate interrupt and display message to the screen
EnterTeamname2:
mov ah,8 ; read a character, which is put in al or lower 8 bits of ax, do not echo to the screen
int 21h
push ax ; store the value entered on the stack
mov ah,2
; display an exclamation mark on the screen, ascii for 21h
mov dl,21h
int 21h
pop ax ; retrieve the character entered
cmp al,1bh ; is the character <ESC>
je Comparison
cmp al,0dh ; or <RET>
je Comparison
mov [di],al ; store the character in the 1st 8 bits of the mem loc di is pointing at
inc di ; increment the index register, i.e. point to the next 8 bits
jmp EnterTeamName2 ; loop
Comparison:
lea di,teamname2 ; load the offset address password2
starts at into di
lea si,teamname1 ; load the offset address password1 starts at into si
xor cx,cx ; clear the cx register
CheckTeams:
mov al,ds:[di] ; copy the 1st character of teamname1 into al
mov bl,ds:[si] ; copy the 1st character of teamname2 into bl
cmp al,bl ; compare the values
jne TeamNamefail ; if the values are incorrect display error
inc di ; increment di to look at the next character in password
inc si ; increment si to look at the next character in password 2
inc cx ; increment the counter register cx
cmp cx,4 ; compare the counter to see if we have exceeded 4 characters
je TeamNameOK ; if we have got this far the first 4 characters match
jmp CheckTeams ; loop until we process 4 characters the rest are not compared
TeamNameOK:
mov ah,9
mov dx,OFFSET msg8 ; display message
int 21h
jmp Onward
TeamNameFail:
mov ah,9
mov dx,OFFSET msg6 ; display message
int 21h
Onward:
mov ah,9
mov dx,OFFSET msg3 ; display message
int 21h
mov ah,9
mov dx,OFFSET Teamname1 ; display teamname1
int 21h
mov ah,9
mov dx,OFFSET msg3 ; display teamname2
int 21h
mov ah,9
mov dx,OFFSET teamname2 ; display password 2
int 21h
mov ah,4ch ; terminate program
int 21h
main ENDP
END main
I do have the following code though, but sadly it doesnt work:
Thanks in advance =]
TITLE (comparinvariableshideinput.asm)
; This program reads 2 messages, compares the values and displays a message if they match or do not match
.model large ; specify a large memory model for this program
.stack 4096 ; allocate 4096 bytes to the stack
.386 ; use the 386 processor instruction set
.data ; define data variables used by the program
;DECLARE VARIABLES
msg byte "please enter your team-name" ; msg is of type byte and overflows to 19 bytes
msg2 byte 0dh,0ah,"$" ; msg is of type byte and includes line feed, carr return and terminate
msg3 byte 0dh,0ah
byte 0dh,0ah ; add line feed and carr return
byte "the team name entered was" ; add string as listed
byte 0dh,0ah,"$" ; add line feed and carr return and terminate char
msg6 byte 0dh,0ah
byte 0dh,0ah
byte "the team names entered do not match", "$"
msg8 byte 0dh,0ah
byte 0dh,0ah
byte "the team names entered match", "$"
char byte 00h ; allocate 0 to varable char
counter dw 0 ; delc
teamname1 byte 40 DUP ('$') ; define variable to store teamname1 with $
teamname2 byte 40 DUP ('$') ; define variable to store teamname2 with $
.code
; INITIALISE REGISTERS
main PROC
mov ax,SEG msg ; move the segment number used by msg into ax
mov ds,ax ; copy the segment number (ax) into ds (the data register used to store the segment used by this program)
mov ah,9 ; copy function 9 (display to screen) into the high bits of reg ax
mov dx,OFFSET msg ; copy the offset (within the segment in ds) of msg into dx (as dx req's offset within segment to start reading message)
int 21h ; generate interrupt and display message to the screen
xor cx,cx ; clear register cx
cld ; clear the direction flag
lea di,teamname1 ; load the effective address of teamname1 (segment + offset) into di so that we can write to it
; PROCESS AND TEST USER INPUT
EnterTeamname1:
mov ah,8 ; read a character, which is put in al or lower 8 bits of ax
int 21h
cmp al,1bh ; is the character <ESC>
je Maintenance
cmp al,0dh ; or <RET>
je Maintenance
mov [di],al ; store the character in the 1st 8 bits of the mem loc di is pointing at or start of buffer
inc di ; increment the index register, i.e. point to the next 8 bits to be written
jmp EnterTeamname1 ; loop
Maintenance:
xor cx,cx
cld
lea di,teamname2
; load teamname2
mov ah,9 ; copy function 9 (display to screen) into the high bits of reg ax
mov dx,OFFSET msg ; copy the offset (within the segment in ds) of msg into dx (as dx req's offset within segment to start reading message)
int 21h ; generate interrupt and display message to the screen
EnterTeamname2:
mov ah,8 ; read a character, which is put in al or lower 8 bits of ax, do not echo to the screen
int 21h
push ax ; store the value entered on the stack
mov ah,2
; display an exclamation mark on the screen, ascii for 21h
mov dl,21h
int 21h
pop ax ; retrieve the character entered
cmp al,1bh ; is the character <ESC>
je Comparison
cmp al,0dh ; or <RET>
je Comparison
mov [di],al ; store the character in the 1st 8 bits of the mem loc di is pointing at
inc di ; increment the index register, i.e. point to the next 8 bits
jmp EnterTeamName2 ; loop
Comparison:
lea di,teamname2 ; load the offset address password2
starts at into di
lea si,teamname1 ; load the offset address password1 starts at into si
xor cx,cx ; clear the cx register
CheckTeams:
mov al,ds:[di] ; copy the 1st character of teamname1 into al
mov bl,ds:[si] ; copy the 1st character of teamname2 into bl
cmp al,bl ; compare the values
jne TeamNamefail ; if the values are incorrect display error
inc di ; increment di to look at the next character in password
inc si ; increment si to look at the next character in password 2
inc cx ; increment the counter register cx
cmp cx,4 ; compare the counter to see if we have exceeded 4 characters
je TeamNameOK ; if we have got this far the first 4 characters match
jmp CheckTeams ; loop until we process 4 characters the rest are not compared
TeamNameOK:
mov ah,9
mov dx,OFFSET msg8 ; display message
int 21h
jmp Onward
TeamNameFail:
mov ah,9
mov dx,OFFSET msg6 ; display message
int 21h
Onward:
mov ah,9
mov dx,OFFSET msg3 ; display message
int 21h
mov ah,9
mov dx,OFFSET Teamname1 ; display teamname1
int 21h
mov ah,9
mov dx,OFFSET msg3 ; display teamname2
int 21h
mov ah,9
mov dx,OFFSET teamname2 ; display password 2
int 21h
mov ah,4ch ; terminate program
int 21h
main ENDP
END main
!