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A Skeleton Boot Sector

Here is a skeleton Boot Sector you could use.

1.    It starts off by switching to the segment offset combination of 07C0:0000 instead of 0000:7C00  

2.    It updates the DS and ES registers to point to segment 07C0. 

3.    Finally it makes sure the boot sector signature  0x0AA55 is put at offset 510.


_Text SEGMENT PUBLIC USE16
org 0
; Program entry point
; Currently we are at 0:7C00
; Would have preferred 07C0:0000
; Dealing with an offset that starts at 0 is easier
; So do a far jump to 07C0:????
EntryPoint:
jmp 0x07C0:AfterData

; Your Data goes here!
DUMMY_DATA db 'boot sector data'

; The rest of your code
AfterData:
; update DS to be 7C0 instead of 0
push CS
pop DS
; update ES also
push CS
pop ES
; create stack
mov ax, 0x0000
mov ss, ax
mov sp, 0xFFFF

;************************************************************
; Your code goes here!
;************************************************************

; Make the file 512 bytes long
TIMES 510-($-$$) DB 0 

; Add the boot signature
dw 0AA55h


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Last updated on 08-November-2002

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