Hi,
You have not really told us a lot of information about any functions in your operating system. It would be interesting to know if you have any input functions, output functions and so on. But judging by your other topic about finding people to join your team, I suspect that you haven't done that much work yet (Feel free to prove me wrong, in that case we can change the code).
I suggest you to read the FASM manual (if you haven't done so already) and I also suggest you to read the Intel manuals (still if you haven't done so already).
Code:
mov bx, Buffer ; Make sure you have DS set to the proper segment
GetInput: ; This will loop as long as the user doesn't press enter
mov ah, 0x00
int 0x16 ; Interrupt 0x16, AH = 0x00 -> GET KEYSTROKE
mov ah, 0x0E ;
int 0x10 ; Interrupt 0x10, AH = 0x0E -> Teletype output
cmp al, 0x0D ; Did the user press enter?
je CheckString ; Then check the string
mov [bx], al ; Save it into the buffer
inc bx ; Make bx point to the next byte in the buffer
jmp GetInput ; Loop it over again
CheckString: ; This function will check if the user typed "hello"
mov cx, 5 ; Move 5 into cx, because there is 5 letters in "hello"
mov si, Buffer ; We will check the buffer against "hello"
mov di, Hello ; ^
repe cmpsb ; cmpsb will compare the byte at es:di from the byte at ds:si. repe will do this cx times and increase di and si each time
je DoSomething ; If it is equal then jump ahead and do something if it is hello
jmp DoSomethingElse ; And if it is not, then do something else
Buffer:
times 16 db 0
Hello db "hello"
Please notice that this is only example code, because I dont know anything about your operating systems functions. And also notice that this does not check for buffer overflow, it does not deal with backspaces, it is case sensetive and so on. I left this for you to do, since I do not want to do all your homework (actually I do not really want to do homework at all, but I do this to point you in the right direction).
Blue