Floppy Disk Help

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Jakevfr

Joined: 03 Feb 2007
Posts: 26

Jakevfr 13 Feb 2007, 03:16

Alright, I'm following a simple little tutorial on making a little OS and I've hit a major problem; whenever I try to run my OS I get this:

Quote:

Invalid system file
Reload disk and press any key to try again

I've created my .bin files and copied them to a floppy but it won't work and I haven't been able to find a topic that tells me how to fix this (although I now know a heck of a lot more about floppys after all the topics I've looked through Razz

)

13 Feb 2007, 03:16

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 13 Feb 2007, 16:14

We need more info, like code for bin, what you used to write .bin file to floppy etc.
Eg: is your bin file 512 bytes in size, with something like this at the end ?

Code:

times 510- ($-start)  db 0
dw 0xaa55

13 Feb 2007, 16:14

Jakevfr

Joined: 03 Feb 2007
Posts: 26

Jakevfr 13 Feb 2007, 17:29

Here's the code I'm trying (It's in NASM format because the tutorial I'm following uses NASM)

Code:

push word 0b800h
pop es
xor di, di
mov [es:di], word 441h

jmp $

times 510 - ($ - $$) db 0
db 55h
db 0aah

Thanks

13 Feb 2007, 17:29

Jakevfr

Joined: 03 Feb 2007
Posts: 26

Jakevfr 13 Feb 2007, 19:15

Sorry for the double post, but I just got it to work. It turns out I was comiling it wrong. Thanks for your help

13 Feb 2007, 19:15

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 13 Feb 2007, 19:21

Just in case more examples:
example1
C:\FASM TEST.ASM TEST.BIN
put it on a floppy with rawrite.

Code:

 org 0x7C00use16;****************************; Realmode startup code.;****************************start:        xor   ax,ax        mov   ds,ax        mov   es,ax        mov   ss,ax        mov   sp,0x7C00;*************************************; Print message.;*************************************       mov ax,0xB800       mov es,ax       lea si,[msg0]       mov di,(80 * 1 + 2) * 2       mov cx,26       cld       rep movsb            jmp  $ msg0 db "  H E L L O   W O R L D !   "      ;*************************************; Make program 510 byte's + 0xaa55;*************************************times 510- ($-start)  db 0dw 0xaa55

example2
With bios.
C:\FASM TEST.ASM TEST.BIN
put it on a floppy with rawrite.

Code:

 org 0x7C00use16;****************************; Realmode startup code.;****************************start:        xor   ax,ax        mov   ds,ax        mov   es,ax        mov   ss,ax        mov   sp,0x7C00;*************************************; Print message.;*************************************        mov  si,msg0        call  print        jmp  $;====================================================;;  print.                                            ;;====================================================;print:        mov   ah,0Eh                       ; Request displayagain1:        lodsb                              ; load a byte into AL from DS:SI        or   al,al                         ; Or AL        jz   done1                         ; Jump 0, to label done1        int  10h                           ; Call interrupt service        jmp  again1                        ; Jump to label again1done1:        ret                                ; Return msg0 db " Hello world! "      ;*************************************; Make program 510 byte's + 0xaa55;*************************************times 510- ($-start)  db 0dw 0xaa55

13 Feb 2007, 19:21

Mac2004

Joined: 15 Dec 2003
Posts: 314

Mac2004 14 Feb 2007, 16:57

Maybe my boot sector example could help you in some way?

http://board.flatassembler.net/topic.php?t=6529

Regards,
Mac2004

14 Feb 2007, 16:57

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