.model small		; It's a flaw of mine ... I really like this model

			; I know I should do a .com with the tiny model.. 

			; but I just love the small :>

.stack 100h		; Plenty stack ;>

.386



.data         

info db 30 dup (0)

right db 'Right CD$'

wrong db 'Wrong CD$'

nomscdex db 'MSCDEX not installed$'

.code

mov ax, @data            ; Make DS&ES point to the DATA

mov ds,ax

mov es,ax



lea edx, nomscdex

xor ebx,ebx

mov eax, 1500h		; MSCDEX installed?

int 2fh

test ebx,ebx

jz exit			





mov edi,10h

nextloop:

mov ecx,edi

mov ax, 150bh		; is drive ECX supported by MSCDEX (is it a cdrom?)

int 2fh

test ax,ax		; ax!=0 if drive is CDrom

jz continiue



mov ax, 440dh

mov dx, offset info

mov bl,5

mov ch,8

mov cl,66h

int 21h			; Fetch volume serial number (same as when you do dir)



mov eax, dword ptr [info 2]

cmp eax, 0ffb7f724h; 	;<<<<calibrate this to fit your own "right" CD

jnz continiue



lea edx, right

jmp exit



continiue:

dec edi			; next drive

jnz nextloop

lea edx, wrong		; not in any drive!

exit:

mov ah, 9h

int 21h



mov ax,4c00h           		; terminate!

int 21h



end