Making a spare boot up floppy - Tks for the answer that I expected

[Barry Yu]

Jeff Vian wrote:

>
>
> Barry Yu wrote:
>
>> Jeff Vian wrote:
>>
>>>
>>>
>>>>
>>> I agree on the utility of booting from CD.  However, the OP had 
>>> asked what he did wrong in trying to make the bootable floppy.  :-)
>>>
>>>
>>> It never hurts ot answer the question that was asked.  :-)
>>>
>>>>>
>>>>> On Sun, 2004-03-28 at 18:42, Jeff Vian wrote:
>>>>> > The easiest way to make a usable (and bootable) image of a boot 
>>>>> floppy
>>>>> > is with dd.
>>>>> > Use "dd if=/dev/fd0 of=boot.img bs=512 count=2440" to create the 
>>>>> file
>>>>> > boot.img that is an exact copy of the floppy.
>>>>> >
>>>>> > That will create a bootable image of the floppy that then can be 
>>>>> put
>>>>> > back onto another floppy using rawrite from dos/windows, or dd 
>>>>> on linux.
>>>>>
>>>>>
>>>>> > Barry Yu wrote:
>>>>>
>>>>> > >I want copy all contents in the bootable floppy into my data 
>>>>> storage partition, and copy them back into a blank floppy in case 
>>>>> I need - I had bad experience in open a blend new box of floppy 
>>>>> and 3 consecutive floppy even not workable at all! I must prepare 
>>>>> if the current boot floppy one day is gone. Moreever, I really 
>>>>> want to know above copy process what have I missed that caused the 
>>>>> new floppy not bootable even with correct contents in it (At least 
>>>>> I can't see what I had missed).
>>>>> > >Thanks for helping.
>>>>>
>>>
>>>
>> Exactly, what I wanted to know is ; Why I can't copy the contents of  
>> a bootable floppy? Because after I have copeid I copared both 
>> floppies (The original and the new copy) I obviously found nothing 
>> wrong but the new floppy just won't work, that is what I want to find 
>> out.
>>
> As I said in my first answer,  making the floppy bootable is NOT the 
> same as copying files to it.
> The boot sector must be written to make it bootable.  Copying files 
> to/from the floppy does not affect the boot sector of the disk, thus 
> it does not make it bootable by the simple act of copying the needed 
> files to the disk.
>
> Making a floppy with "mkbootdisk" writes the boot sector to make it 
> bootable, as does "sys" in dos/windows.  Then my method of creating a 
> duplicate of the bootable diskette once made will recreate the boot 
> sector exactly as written so the copy is also bootable.
>
> Please note, that if a floppy has any bad sectors when formatted it 
> CANNOT be used to read/write an exact image since the image will be 
> the size of the full disk and bad sectors will mean the image is not 
> restored properly.
>
>
Now this time I've really  gotten the asnwer that I expected and thanks 
a lot.