Category : Utilities for DOS and Windows Machines
Archive   : FDFORM18.ZIP
Filename : FDBOOT.ASM

Output of file : FDBOOT.ASM contained in archive : FDFORM18.ZIP
page 66,128
cseg segment para public 'CODE'
assume cs:cseg

org 100h ;Allow Boot-Sector as COM-File
begin: jmp short start ;Jump
bpb db 3FH DUP (0) ;Reserve enough space for BPB

start proc far
cli ;Clear Interrupts, while modifying stack
xor ax,ax ;Zero AX
mov ss,ax ;Set SS...
mov sp,7c00h ;..and SP below Code
mov ax,7b0h ;Set Segment-Registers that Offset is 100H
push ax ;Push Segment twice
push ax
pop ds ;Get Segment in DS
pop es ;and also in ES
mov si,100h ;Set Source to 100H
mov di,300h ;Set Destination to 300H
mov cx,100h ;Set Count to 512 Bytes (1 Sector)
rep movsw ;Move Code
mov ax,7d0h ;New Segment at 7d0h (+20H)
push ax ;Push Segment three times
push ax
push ax
pop ds ;Get new segment in DS
pop es ;and also in ES
mov ax,offset entry ;Offset of next instruction
push ax ;Push to stack
ret ;and pop it to CS:IP
start endp

entry proc far
sti ;Start Interrupts again
mov si,offset text1 ;Move SI to text
call output ;display to screen
mov ax,201h ;AH=2 (read sector), AL=1 (count)
mov cx,1 ;CH=0 (Track), CL=1 (Sector)
mov dx,128 ;DH=0 (Head), DL=128 (Fixed Disk C)
xor bx,bx ;Segment of Transfer buffer
push bx ;Push to Stack
pop es ;Get Segment in ES
mov bx,7c00h ;Offset of Transfer buffer
push es ;Push Segment...
push bx ;And Offset to stack
int 13h ;Read from Harddisk
jc error ;Jump if error
cmp word ptr es:7dfeh,0aa55h ;Valid Boot Secotor?
jnz error ;No, error
ret ;Continue with Boot-Sector of C:

error: mov si,offset text2 ;Move SI to text
call output ;display to screen
loop1: mov ah,1 ;Get Status of...
int 16h ;...Keyboard buffer
jz boot_new ;if keypressed, reboot
xor ah,ah ;flush....
int 16h ;...Keyboard Buffer
jmp loop1 ;And try again
boot_new: xor ah,ah ;flush...
int 16h ;...Keyboard buffer
xor dx,dx ;Zero DX
int 19h ;Reboot
entry endp

output proc near
loop_o: lodsb ;Get one character
or al,al ;Is it zero?
jnz weiter ;No, continue
ret ;else return
weiter: push si ;Save SI
mov ah,0eh ;Output character...
int 10h ; AL to screen
pop si ;restore SI
jmp short loop_o ;repeat loop
output endp

text1 db 'FDBOOT Version 1.8',10,13
db 'No Systemdisk. Booting from harddisk.',10,13,0
text2 db 'Cannot load from harddisk.',10,13
db 'Insert Systemdisk and press any key.',10,13,0

text1 db 'FDBOOT Version 1.8',10,13
db 'Keine Systemdiskette. Starten von Festplatte.',10,13,0
text2 db 'Kann nicht von der Festplatte starten.',10,13
db 'System-Diskette in Laufwerk A: einlegen',10,13
db 'Anschlieáend eine Taste drcken',10,13,0

org 2feh
db 55h,0aah

cseg ends
end begin

  3 Responses to “Category : Utilities for DOS and Windows Machines
Archive   : FDFORM18.ZIP
Filename : FDBOOT.ASM

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: