suhonen@tukki.jyu.fi (Timo Suhonen) (11/14/90)
In article <mboen.658534305@peun33> mboen@nixdorf.de (Martin Boening) writes:
Well, you'd better NEVER power up with any disk in drive A. If the boot
sector is executable, it'll be executed. And that's with a ROM OS!
If the boot sector is a virus, you'll get hit by a virus. That's all there
is to a boot sector virus. It's true though, that there probably won't be
many link viruses infesting command.com, cause there's no command.com.
At least my ST boots from hd weather or not I have a bootable disk in
drive A: (assuming that my hd is turned on and is running at full speed).
So there is no way a virus can infect at the boot time.
Those miserable Messy-Dog systems DO boot from disk if there is a bootable
disk in drive A:
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Timo Suhonen I am logged in, therefore I am suhonen@funic.funet.fi
suhonen@kunto.jyu.fi
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Ajatukset(?) ovat omiani (jos eiv{t ole varastettuja), eiv{t yliopiston.andrew@cs.utk.edu (Andrew Krzywdzinski) (11/14/90)
In article <SUHONEN.90Nov14122549@tukki.jyu.fi> suhonen@tukki.jyu.fi (Timo Suhonen) writes: >At least my ST boots from hd weather or not I have a bootable disk in >drive A: (assuming that my hd is turned on and is running at full speed). >So there is no way a virus can infect at the boot time. > That's interesting... I happen to have a hard disk too, and my floppy is viri-protected (I assume by a program in the boot sector) by George Woodside's vkiller. Anyway, even though I boot from the hd, it always executes the boot sector on the floppy ! One of us has to be wrong, then... -andrew krzywdzinski (andrew@cs.utk.edu)
psurge@cs.utexas.edu (Troy Carpenter) (11/15/90)
In article <1990Nov14.140643.15703@cs.utk.edu>, andrew@cs.utk.edu (Andrew Krzywdzinski) writes: > > That's interesting... I happen to have a hard disk too, and my floppy > is viri-protected (I assume by a program in the boot sector) by George > Woodside's vkiller. Anyway, even though I boot from the hd, it always > executes the boot sector on the floppy ! > One of us has to be wrong, then... > > -andrew krzywdzinski (andrew@cs.utk.edu) The ST will look to the boot sector of the floppy disk to see if it is executable before booting the HD. However, this does not mean that the HD needs to have the floppy in the drive. I read an article not long ago that stated the boot up procedure was like this: (I think Dave Small wrote it) 1. The ST looks to the floppy and checks to see if it is autobooting. (try putting a autobooting game and see if your hard drive starts up.) 2. If the disk is not autobooting, or the disk IS NOT THERE, then it will try to boot the hard drive. (this happens on systems with no HD also) 3. If the hard drive is not autobooting, or there is no hard drive then control returns to the floppy drive and the auto folder. 4. If there is still no floppy disk, then the default desktop comes up. Note: This is for TOS in ROM. So Yes, the Hard drive does check the boot sector, but it is not needed to boot a hard drive that is Autobooting. Note that it will take slightly longer if there is not disk in the drive because the floppy drive must time out before control passes to the Hard drive. You can see this process at work on your own system by setting up cases that fail one of the above conditions (ie put a autobooting game disk, or turn off your hard drive and boot without a floppy in the drive). Troy Carpenter Department of Computer Sciences THE University of Texas, Austin psurge@cs.utexas.edu "You're so open minded that your brain leaked out" - Steve Taylor *>>>>>>>>>>>>>>>>>> The best thing in life costs exactly that <<<<<<<<<<<<<<<*
Erik-jan.Vens@samba.acs.unc.edu (Erik-jan Vens) (11/15/90)
Well, my 1040ST (and I'm working right now on it) when linked to my MegaFile 60 (and it always is), always boots from the harddisk. Whether or not there is a floppy in the drive. But I am told this is TOS specific. I use TOS 1.4. Erik-Jan. Vens@Rug.NL
apratt@atari.UUCP (Allan Pratt) (11/15/90)
A "bootable" floppy is one with an executable boot sector (checksum $1234). If you have a "bootable" floppy in the drive, the boot sector will be executed before the hard disk is hit. The executable code in the boot sector can, for example, install a virus, then end with "rts" to return to the ROMs, at which time the hard disk will boot. This is how the Key virus (and all other boot-sector viruses) work. You are safe from them if you have a disk in the drive which does NOT have an executable boot sector, or no disk at all. It's best to write-protect this disk, so nothing can write a virus into the boot sector. ============================================ Opinions expressed above do not necessarily -- Allan Pratt, Atari Corp. reflect those of Atari Corp. or anyone else. ...ames!atari!apratt
suhonen@kunto.jyu.fi (Timo Suhonen) (11/15/90)
In article <1990Nov14.140643.15703@cs.utk.edu> andrew@cs.utk.edu (Andrew Krzywdzinski) writes:
That's interesting... I happen to have a hard disk too, and my floppy
is viri-protected (I assume by a program in the boot sector) by George
Woodside's vkiller. Anyway, even though I boot from the hd, it always
executes the boot sector on the floppy !
One of us has to be wrong, then...
If I got you right, your system (if floppy inserted in drive) executes floppy's
boot sector and then boots from hd, right? I have not tested that... Maybe
mine do the same thing... I just thought that if it excutes boot sector from
a floppy, it can't anymore go on booting from hd.
Assume that your boot sector on a floppy has code to load disk-based TOS
(really old one) from a floppy. Will your system still somehow boot from hd?
How?
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Timo Suhonen I am logged in, therefore I am suhonen@funic.funet.fi
suhonen@kunto.jyu.fi
Moderator for ftp site funic.funet.fi (128.214.6.100) Atari ST dirljdickey@aftermath.waterloo.edu (L.J.Dickey) (11/20/90)
In article <2744@atari.UUCP> apratt@atari.UUCP (Allan Pratt) writes: | A "bootable" floppy is one with an executable boot sector (checksum | $1234). If you have a "bootable" floppy in the drive, the boot sector | will be executed before the hard disk is hit. [...] I am curious about the search path during boot up. Am I right that it goes something like this: A: [boot.sector] C:\something.SYS A:\AUTO\something.PRG Lee Dickey