Path: utzoo!mnetor!tmsoft!torsqnt!hybrid!scifi!bywater!uunet!garfield!roger From: roger@garfield.cs.mun.ca (Roger White) Newsgroups: comp.sys.cbm Subject: Re: GEOS Companion Disk Keywords: Simple fix... Message-ID: <1991Feb24.213914.18800@garfield.cs.mun.ca> Date: 24 Feb 91 21:39:14 GMT References: <1991Feb17.234810.11358@garfield.cs.mun.ca> <1991Feb20.063301.26802@evax.arl.utexas.edu> Organization: CS Dept, Memorial University of Newfoundland Lines: 56 In article <1991Feb20.063301.26802@evax.arl.utexas.edu> cs4344af@evax.arl.utexas.edu (Fuzzy Fox) writes: >In article <1991Feb17.234810.11358@garfield.cs.mun.ca> roger@garfield.cs.mun.ca (Roger White) writes: >>4. Do what I did... [...edit the file type bytes in the directory...] > >I fail to see how this avoids the Berkeley Trojan (isn't that a great >name for it?)... The Trojan does NOT look at the directory at all, but >instead checks track 18, sector 0, byte offset $BD, which is set to 0 >for a work disk, "P" for a master disk, and "B" for a boot disk. If the >byte is "B", and the copy protection fails, then the Trojan zaps the >first three entries of the directory to zeroes, WITHOUT checking to see >what they are. In effect, you can defeat the Trojan another way by >moving the 3 boot files to another page on the disk, and making sure >that no file ever occupies one of the first three slots on page one. >(But of course GEOS won't let you move the boot files, will it? Gee, I >wonder why?) You'll have to use another disk editor to do this. > >Anyway, I contend that you have just been lucky so far. I believe if >you boot GEOS and remove the boot disk as your first action after >booting, you will most likely not have a problem with your files >disappearing. Try moving files around on the DeskTop for a while, and >perhaps you will see the files disappear. > >-- >David DeSimone, aka "Fuzzy Fox" on some networks. /!/! >INET: an207@cleveland.freenet.edu / .. >Q-Link: Fuzzy Fox / --* >Quote: "Foxes are people too! And vice versa." / --- Well I can't see how your explanation works... I made three copies of Geos 128 V2 without switching the filetypes. Each time while copying files over to/from that disk I lost the system boot files. All three of the disks were not able to boot again. I have been now using my 'fixed' disk for the past 6 months with no problem. I copy files to it, from it, load applications from it, delete files from it... everything you can do with it and the boot files are still there. I have two disks created like this (one for my father, one for me) and I have not lost a boot file since. If it is only a coincidence then it must be a once (twice?) in a lifetime thing. I have yet to lose a boot file in 6 months, but I lost 3 disks in only one day without changing the file type. I have never looked into the Berkeley Kernal, but I believe it deletes all the system boot files... not only the first three. Therefore changing the system boots to applications will fix the 'Berkeley Trojan'. Why don't someone else try it and report to the net their finding, all we need is one person to say that their boot files were erased to show that it doesn't work (except for me :-). I haven't tried it with the 64 version, but the 128 version works perfectly for me. Roger. -- Boot it up? I did A LOT of that!| Roger White (Sam-Cheers) | Memorial University of Newfoundland --------------------------------| St. John's, Newfoundland, Canada ..uunet!odie.cs.mun.ca!roger, roger@odie.mun.edu, roger@odie.cs.mun.ca Brought to you by Super Global Mega Corp .com