Rank: ? (1)
Member #: 27655

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

Rank: ? (5)
Member #: 28723

hi,

there were some mistakes, especially the input function 0Ah /Int 21h works a bit different,
but the general idea was ok, seems to be working now (tested with 16 bit masm)

Code: