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PC XT DOS antivirus that fits in 360 Kb disk

skouris33

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Feb 21, 2014
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Larisa, Greece
Hi, I would like to ask you if there is an antivirus program for DOS PC XTs that fits in a 360 Kb disk, in order to scan my floppy drive, thank you
 
Hi, I would like to ask you if there is an antivirus program for DOS PC XTs that fits in a 360 Kb disk, in order to scan my floppy drive, thank you

Don't you mean "scan a disk in the other drive"? My guess is that anything that can fit in 360K is going to be ineffective or insufficient. I just checked my F-Prot files from a years ago, and the virus definition file alone is 580K. My thought is that if you have a lot of old disks that need to be checked, then you're better off setting up a machine that has a hard drive - even if it's just a quick or temporary build.
 
I remember using a version of mcafee back then, not sure about the version but there was definitely one that fits in a DD 5 1/4 floppy. Of course it will only address dos viruses of its time, so as already said maybe it would be better to check the disks on another computer
 
I have NOD antivirus (ESET today) on one 360k floppy, from year 1991. But in Slovak language :)
nod.jpg
 
I also had 360KB virus scanners back when the only viruses I found were Stoned and Michaelangelo. I used to use old versions of Mcafee but I couldn't find them with quick google searches. I remember there was scan.exe and clean.exe. Mcafee even had a public FTP server with the registered versions on it for years, their security wasn't great. I still have VET anti virus on a 360KB floppy.
 
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Would a new virus even bother with an old pc? Wouldn't it just look at the hardware and hang itself?
What I think was suggested: Say that the latest anti-virus DOS program that fits on a 360K sized DOS boot floppy is dated 1990, then DOS infecting viruses post 1990 won't be detected.
 
I have SCAN76-C from April, 1991 if that's of any help to you.

I also have SCAN 9.30 V117 from July, 1994

Both fit on a 360K disk.​
 
This is where I'd highly suggest using a newer antivirus software on an in-betweener system. A newer system that can run the newer antivirus software but still has a 5.25" drive. The problem you'll find is what folks already mentioned. Obsolete virus scanners can't find all viruses or variations, and also a lot of those early virus scanners really sucked (didn't pick up half the infections in the first place). The best dos one I used was Norton at the time it found most of my friends and my virus collection. I remember we tested Norton (nav), Mcafee, Thundersomething, f-prot, dr solomons, and IBM antivirus. Microsoft also had their own from CentralPoint in later dos versions (msav I think).

However this was in the 386/486 days with higher versions of dos and 1.2MB disks. The biggest part of the virus scanner is the definitions which they would sometimes compress or create a mini version for the floppy recovery disks for the most basic checks.
 
Would a new virus even bother with an old pc? Wouldn't it just look at the hardware and hang itself?

I doubt it, but my question would be if it still included the early virus like Stoned and Michaelangelo. Perhaps they would, but I also don't think that most modern malware is not capable of infecting 360K disks and the type of software you would have on those. That's why my only DOS virus scanner is F-Prot from 1998. My theory is that it will catch anything that I'm going to encounter on old unknown disks.

I just looked and F-Prot 2.28b (1998 ) takes up just a hair under 2MB. Like barythrin, I strongly suggest using a newer system with a 5.25 drive - even if you just install the drive temporarily. Otherwise the effort won't be effective.

That said, we haven't heard from skouris33 since he started this thread. Perhaps he is looking to keep the system true to period - in which case our advice is moot.
 
I'm interested in this.
I likely will only be mostly concerned with getting a program disks from a garage sale or possibly ebay and my interest in these 360K disks would be prior to 1991.
Just incase there's 25yr old viruses lingering on them.
 
I'm interested in this.
I likely will only be mostly concerned with getting a program disks from a garage sale or possibly ebay and my interest in these 360K disks would be prior to 1991.
Just incase there's 25yr old viruses lingering on them.
That's why I keep a virus scanner around. I don't think there is a very big chance of catching anything much these days, but when you're talking about old unknown disks then that's another matter.

Anyone who's had a kid in school during the floppy years knows that not ONE floppy that has been to school and back is clean.

Of course, and the OP might be interested in this, there's always "fdisk /mbr" which solves quite a lot of situations.
 
If the machine only has floppy drives then you could write protect a known clean boot floppy and do cold boots for each new disk, so if there was a virus, it can't spread. 5.25" viruses aren't that common, most people who would have kept disks that long probably know what they are doing. I have viruses on 360KB floppies but they are clearly marked since I was collecting them at the time. Unlikely to find a virus newer than 1991 on a 5.25" 360KB floppy.
 
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Thank you all for your replies and sorry for not replying earlier but I have been sick for few days. I'm going to transfer the floppy drive into a newer machine and then run an antivirus. Again thank you all
 
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