On Sun, 14 Sep 1997, Leigh Morresi wrote:
> Well im getting closer to fully understanding bootable code.
> Ive looked at some examples and they say that the DATA offset has to be
> 7C00h, now my problem is...
> 
>        mov ah,09
>        mov dx,OFFSET string
>        int 21h
It's not possible to use DOS calls in boot code.  
; Mini OS-  Demos a simple boot sector.
;
;  Assemble as a COM file, then write to a floppy:
;  debug mini.com
;  -w 100 0 0 1      ;be careful with this- it destroys DOS loader.
;  -q                ;Use only 100 0 0 1- read debug docs.
;
cseg segment
assume cs:cseg,ds:cseg
org 0                           ;Zero, BIN or COM
Begin:
        mov ah,3
        xor bh,bh
        int 10h                 ;Get cursor location.
        mov ax,1301h
        mov bl,7h
        mov bp,offset txt + 7C00h
        mov cx,0Fh
        int 10h                 ;Display welcome text.
main:
        mov ah,0
        int 16h
        mov bx,7
        mov ah,0Eh
        int 10h                 ;Print keypresses to screen.
        jmp main
txt db 'Start typing!', 0Dh, 0Ah
        org 510
        dw  0AA55h              ;Some BIOS require this.
cseg ends
end Begin
--- ifmail-tx (i386 Linux)
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