Programming Forums > Application Development > Assembly

sheeba · Mar 25th, 2005, 12:44 PM

Hi , I need some help with this program
I've tried figureing out myself for the last 2 days but can't.
After the user enters a number , that number is supposed to be doubled and displayed , doubled & displayed again , in the loop 5 times.

thanks

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.model small
.stack 100h
.data
input db 0dh,0ah,"Please type an integer between 1-1000h:",0
two dw 2h
.code
extrn Writeint:proc,Writestring:proc,Readint:proc,Crlf:proc
main proc
   mov ax,@data
   mov ds,ax
   mov cx,5
   mov dx,offset input
   call Writestring
   call Readint
   call Crlf
   mov bx,16
   call Writeint
   next:
     mul two
     mov bx,16
     call Writeint
   loop next
   mov ax,4c00h
   int 21h
 main endp
 end main

brkstf · Mar 25th, 2005, 3:44 PM

the cool way to do this is to shift the register to the left. no need to multiply by two.

Mjordan2nd · Mar 25th, 2005, 5:28 PM

What seems to be wrong with your code?

sheeba · Mar 25th, 2005, 6:23 PM

Thanks for the replies.
It compiles , links , & when I try to run it , & type a number , & press enter the dos window shuts down ??

sheeba · Mar 25th, 2005, 6:24 PM

How would I do that brkstff?

Mjordan2nd · Mar 25th, 2005, 7:24 PM

There should probably be a shl instruction for whatever assembler you may be using. It works because -- well, think about it, the bit to the left is double the current bit. Take this example:

The value five has this binary representation:

101

you shift left and you get

1010

which is 10

shift left again and you get 20

10100

sheeba · Mar 26th, 2005, 12:39 AM

Thanks im going to work on it , see if I can figure it out

Mar 25th, 2005, 12:44 PM	#1
sheeba Newbie Join Date: Mar 2005 Posts: 8 Rep Power: 0	Doubling numbers Hi , I need some help with this program I've tried figureing out myself for the last 2 days but can't. After the user enters a number , that number is supposed to be doubled and displayed , doubled & displayed again , in the loop 5 times. thanks (Toggle Plain Text) .model small .stack 100h .data input db 0dh,0ah,"Please type an integer between 1-1000h:",0 two dw 2h .code extrn Writeint:proc,Writestring:proc,Readint:proc,Crlf:proc main proc mov ax,@data mov ds,ax mov cx,5 mov dx,offset input call Writestring call Readint call Crlf mov bx,16 call Writeint next: mul two mov bx,16 call Writeint loop next mov ax,4c00h int 21h main endp end main .model small .stack 100h .data input db 0dh,0ah,"Please type an integer between 1-1000h:",0 two dw 2h .code extrn Writeint:proc,Writestring:proc,Readint:proc,Crlf:proc main proc mov ax,@data mov ds,ax mov cx,5 mov dx,offset input call Writestring call Readint call Crlf mov bx,16 call Writeint next: mul two mov bx,16 call Writeint loop next mov ax,4c00h int 21h main endp end main

Mar 25th, 2005, 5:28 PM	#3
Mjordan2nd The Supreme Ruler Join Date: May 2004 Location: Houston Posts: 1,476 Rep Power: 6	What seems to be wrong with your code? __________________ "Every gun that is made, every warship launched, every rocket signifies, in the final sense, a theft from those who hunger and are not fed, from those who are cold and are not clothed. The world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children." - Dwight D. Eisenhower

Mar 25th, 2005, 7:24 PM	#6
Mjordan2nd The Supreme Ruler Join Date: May 2004 Location: Houston Posts: 1,476 Rep Power: 6	There should probably be a shl instruction for whatever assembler you may be using. It works because -- well, think about it, the bit to the left is double the current bit. Take this example: The value five has this binary representation: 101 you shift left and you get 1010 which is 10 shift left again and you get 20 10100 __________________ "Every gun that is made, every warship launched, every rocket signifies, in the final sense, a theft from those who hunger and are not fed, from those who are cold and are not clothed. The world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children." - Dwight D. Eisenhower

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Mar 25th, 2005, 3:44 PM	#2
brkstf Programmer Join Date: Feb 2005 Posts: 89 Rep Power: 4	the cool way to do this is to shift the register to the left. no need to multiply by two.

Mar 25th, 2005, 6:23 PM	#4
sheeba Newbie Join Date: Mar 2005 Posts: 8 Rep Power: 0	Thanks for the replies. It compiles , links , & when I try to run it , & type a number , & press enter the dos window shuts down ??

Mar 25th, 2005, 6:24 PM	#5
sheeba Newbie Join Date: Mar 2005 Posts: 8 Rep Power: 0	How would I do that brkstff?

Mar 26th, 2005, 12:39 AM	#7
sheeba Newbie Join Date: Mar 2005 Posts: 8 Rep Power: 0	Thanks im going to work on it , see if I can figure it out

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Programming Forums > Application Development > Assembly

Doubling numbers