Why do we see a:\> even when booting from CD.

[desidud]

while we boot from HD we see C promt.

while booting from floppy we see A prompt &

when booting from bootable CD we still see A prompt...why so?

i have 4 partitions labelled as C,D,E,F & G(dvd rw). when trying to change driver letter of any of the drive by going to administrative tools & then to computer management, then using disk management i never see letters 'A' & 'B', why so?

[redxii]

floppy emulation?

[desidud]

what is the need of floppy emulation. cant bootable cd be created without floppy emulation? n what is floppy emulation, kinda confused

[Glenn9999]

I don't know the decisions or the whys of why bootable CDs (El Torito) were done this way. But anyhow, when you make a bootable CD, you have to make a floppy image and then burn the rest of the data. When the CD boots, it uses the floppy image, and then as part of the floppy image you have to provide CD-ROM drivers.

My guess is to be compatible with most systems, since most systems only know how to boot from floppy disks or hard drives.

[jaclaz]

Maybe this (and links therein) clear a bit the matter:

http://www.911cd.net/forums//index.php?sho...20263&st=11

jaclaz

[desidud]

I don't know the decisions or the whys of why bootable CDs (El Torito) were done this way. But anyhow, when you make a bootable CD, you have to make a floppy image and then burn the rest of the data. When the CD boots, it uses the floppy image, and then as part of the floppy image you have to provide CD-ROM drivers.

My guess is to be compatible with most systems, since most systems only know how to boot from floppy disks or hard drives.

tnx glen for ur input..but why to have or to create a floppy image to make bootable cd

[desidud]

Maybe this (and links therein) clear a bit the matter:

http://www.911cd.net/forums//index.php?sho...20263&st=11

jaclaz

excellent!! just check it out..its like going deeper n deeper in the que asked. tnx a lot jaclaz..will surely increase my knowlege too bout bootable cd's n how they r made.

just incase i have any more queries regarding the same, hopefully it will be replied with too

tnx once again...

[jaclaz]

excellent!! just check it out..its like going deeper n deeper in the que asked. tnx a lot jaclaz..will surely increase my knowlege too bout bootable cd's n how they r made.

just incase i have any more queries regarding the same, hopefully it will be replied with too

tnx once again...

No prob, mate.

The matter is something that is quite commonly asked, but for which there is not (or at least I never managed to find it) a full all-in-one-place explanation, and hard-disk emulation is yet a scarcely documented feature.

One of the best reference is this one :

http://www.geocities.com/chrootstrap/cdrom...our_kernel.html

There are three ways to boot from a CDROM: no emulation booting, floppy disk emulation, and hard disk emulation. We will look at two of them, no emulation and floppy disk emulation.

(bolding is mine)

jaclaz

Edited January 10, 2008 by jaclaz