Assembly

Hello!
I need to make a programm in assembly (it´s better to use Emu8086) that
recieves the STRING from the keyboard and than compress it in this way: input string--> aaabbcddd output string--> 3a2b1c3d.
I know that it is very simple, but I´m just a beginner and can´t make it. I have just one day till tomorrow afternoon. Hope You´ll help me. Thnks

I have an exemple of a code here, but it doesn´t work

.model small
.data
inputstr db 80 dup (' '),'$' ;uncompressed input string & read from keyboard
outputstr db 80 dup (' '),'$' ;compressed output string & displayed
.code
start: mov ax,@data ;Prepare access to Data Segment
mov ds,ax
mov ah,0Ah ;DOS function "Read from file or device"
mov bx,0 ;Standard input device (keyboard)
mov cx,80 ;Maximum length of read input string
mov dx,offset inputstr ;Memory address of read input string
int 21h ;Call DOS function dispatcher
sub ax,2 ;Decrement by 2 the actual input string length(EOL)
mov si, offset inputstr
mov di, offset outputstr
L1: mov bx,si ;Check if we arrived the end of input string (While-type loop)
sub bx,offset inputstr
cmp bx,ax ;Compare with the length of read input string
je L4 ;If so jump to finish
mov cl,1 ;initialize the character counter
L2: mov dl,[si] ;Read the character
cmp dl,[si+1] ;Compare with the next character
jne L3 ;If not equal jump to constructing output string
inc cl ;If equal increment counter
inc si ;And address of next character
jmp L2 ;Repeat counting the current character
L3: mov [di],dl ;Construct the compressed output string. Save character
inc di
add cl,'0' ;Simple single digit conversion to ASCII
mov [di],cl ;Save the counter
inc di ;Prepare for next character
inc si ;
jmp L1 ;Repeat for next character (End of While-type loop)
L4: mov ah,09h ;DOS function "Write string to standard output"
mov dx,offset outputstr ;Display decompressed output string
int 21h ;Call DOS function dispatcher
mov ah,4ch ;DOS function "Exit"
int 21h ;Call DOS function dispatcher
end start

Which assembler are you using? There are literally dozens of assemblers for the x86 processors, each of which take a different syntax. From the code, I gather you are using Turbo Assembler, which is fairly widely used in coursework.

The Language Resources thread has an extensive list of we sites for assembly, including some specifically about Turbo (and other common assemblers). A quick review of these may give you some information you could use.

I Use o Emu8086. I have the book about it, but I just can´t find out what´s wrong with this code. The program does not print the final result!!
Thank you for answer.