[BITS 16]
[ORG 0x7C00]

;Program that prints a square, student details and favourite movie.

top:
    ;; Put 0 into ds (data segment)
    ;; Can't do it directly
    mov ax,0x0000
    mov ds,ax
    ;; si is the location relative to the data segment of the
    ;; string/char to display


    mov si, eightSquareDots ;Moves the eightSquareDots string into the system input and continues to read one character at a time into the buffer until it encounters a null cahracter.
                ;which will indicate the the string has ended at which point the next string will be printed in the same way.
    call writeString ;Calls the writeString function.
    mov si, eightSquareDots ;Repeats the same procedure as the one above.
    call writeString
    mov si, eightSquareDots
    call writeString
    mov si, eightSquareDots
    call writeString
    mov si, eightSquareDots
    call writeString
    mov si, eightSquareDots
    call writeString
    mov si, eightSquareDots
    call writeString
    mov si, eightSquareDots
    call writeString

    mov si, studentName    ;studentName variable.
    call writeString ; the writeString function prints the variable to the terminal.
    mov si, studentCourse ;studentCourse variable.
    call writeString ; Performs the same action as above.
    mov si, favouriteMovie ;favouriteMovie variable.
    call writeString ; Performs the same action as above.
    jmp $ ; Spin
writeString:
    mov ah,0x0E ; Display a chacter (as before)
    mov bh,0x00
    mov bl,0x07
nextchar:
    Lodsb ; Loads [SI] into AL and increases SI by one
    ;; Effectively "pumps" the string through AL
    cmp al,0 ; End of the string?
    jz done
    int 0x10 ; BIOS interrupt
    jmp nextchar
done:
    ret
    ;This section of code contains the variables used to print text on the screen.
    studentName db 'Name:  Martin Vasilev' ,13,10,0 ;Null - terminated
    studentCourse db 'Course: Computer Science' ,13,10,0 ;Null -terminated
    favouriteMovie db 'Favourite Movie: Ex Machina' ,13,10,0 ;Null -terminated
    eightSquareDots db '........' ,13,10,0 ;Null - terminated
    times 510-($-$$) db 0
    dw 0xAA55