Question about DOSBox and mounting and installing?

[Tawmis]

Seems the 3.5" floppies I kept in a plastic case, faired MUCH better than the ones I left in the game box. I am running into more problems with the 3.5" that had been left in the game boxes! Gone through about 30 of them - and I'd say 6 of them I had to use the program you mentioned to recover one or two files off the disk. (Usually the VOL.x or RESOURCE.x files - the largest on the disk). And the recover is SLOW moving when it needs to recover it...

[Collector]

You have a fair task ahead of you, but best to do it before anymore disks become unreadable.

[Tawmis]

You have a fair task ahead of you, but best to do it before anymore disks become unreadable.

Yeah! That's why I am doing it now... I have probably 20 more (Sierra) games to go through. (Some, however, I have found are multiple copies that have the same version # on the disks) - also some, I got on CD or collections (so I am not too terribly worried if some of those tank out on me).

I just wish I had an older computer still that had a 5.25" drive; can't count how many of my (Sierra) games are on 5.25" disks. And they never made a 5.25" USB (which is pretty amazing; you figure SOMEONE would have made it; for the sole purpose of transferring data).

[Tawmis]

That was painful. Over 2 hours to copy/save the RESOURCE.000 file. But it worked! So worth it in the end, I suppose!

[Qbix]

I would do some md5sum checks on the copied files if I were you with collector or somebody else who has the same version as you. (just to be safe)

[Tawmis]

I would do some md5sum checks on the copied files if I were you with collector or somebody else who has the same version as you. (just to be safe)

So I found this: http://www.winmd5.com/

But I am not too clear what MD5SUM does exactly?

[adeyke]

It's a way to check if files are identical. If they are, they'll have the same MD5 value. If they aren't (e.g. because the transfer was incomplete or corrupted), they almost certainly won't have the same MD5 value.

[Collector]

The file hash can be considered a file's finger print. It is the best way to ID a file. If two files have the exact same hash the files are identical. The game ID tool I have been working on that you downloaded last night can get the MD5 of a file. For convenience I use this shell extension. Just select the "File Hashes" tab of the file properties dialog (context menu > "Properties"). It will display CRC, MD5 and SHA hashes.

With the SQ1VGA crash that Dot had I was able to determine that she had a couple of corrupted files because all of the files had the right MD5 except for two that she had recovered. She used the FileLister.exe that I had attached in that thread which generated MD5s of all of the files.

[adeyke]

If two files have the exact same hash the files are identical.

That's overstating it a bit. If someone is deliberately trying to get a hash collision, it's possible for them to do so (especially if you aren't also checking the file size). Just an MD5 value comparison of two files isn't good enough for security.

What we can say, however, is that in situations where no one is trying to trick you, it's extremely unlikely for two particular, different files to have the same hash and that having the same hash makes it extremely likely that these files are identical.

[Tawmis]

A bit of side thinking -

I remember back in the day - using a program called "CopyIIPC" to copy games - but, am I misremembering - in that Sierra used an odd trick about writing to a specific sector that couldn't be copied - as a form of preventing copying the files?

[Collector]

@adeyke, we are not talking about security usage of MD5, but merely as a tool to determine if a file is corrupted or to match a replacement file. MD5 is fine for that.

Tawm, the copy protection that you are talking about was CPC. It faked a bad track on the diskette to hide part of the program to launch the game. This is what causes some AGI games to demand the original disk before it will start. It is also why you cannot start such games on modern Windows. Even if you have the original disks it cannot access the "bad" track without low level access, which modern Windows will not allow. There used to be the old "Sierra Unprotect" (SUP) by Anders Olsson that you could remove the need to read the track as well as Brian Provinciano's "AGI Decrypt" that would create a new "AGI.EXE" launcher. Both of these are, unsurprisingly DOS and require low level access to get the key. As such they do not work on moder Windows. The good news is that siastbill1 created a new modern Win32 version of AGI Decrypt that does not require that low level access. That version detection tool I gave you includes it.

As to CopyIIPC, it will not run on Modern Windows. I don't remember for sure, but I believe it required a special (ISA?) controller card. If you want to copy such disks these days you need something like the KryoFlux.It has a USB interface so you can use it on a modern PC. It can read and write that hidden track. It can also read and write disks from other platforms, such as booter, Amiga, Atari and Apple. It can give you a USB for an old 5.25" floppy drive.

[Tawmis]

Tawm, the copy protection that you are talking about was CPC. It faked a bad track on the diskette to hide part of the program to launch the game. This is what causes some AGI games to demand the original disk before it will start. It is also why you cannot start such games on modern Windows. Even if you have the original disks it cannot access the "bad" track without low level access, which modern Windows will not allow. There used to be the old "Sierra Unprotect" (SUP) by Anders Olsson that you could remove the need to read the track as well as Brian Provinciano's "AGI Decrypt" that would create a new "AGI.EXE" launcher. Both of these are, unsurprisingly DOS and require low level access to get the key. As such they do not work on moder Windows. The good news is that siastbill1 created a new modern Win32 version of AGI Decrypt that does not require that low level access. That version detection tool I gave you includes it.

As to CopyIIPC, it will not run on Modern Windows. I don't remember for sure, but I believe it required a special (ISA?) controller card. If you want to copy such disks these days you need something like the KryoFlux.It has a USB interface so you can use it on a modern PC. It can read and write that hidden track. It can also read and write disks from other platforms, such as booter, Amiga, Atari and Apple. It can give you a USB for an old 5.25" floppy drive.

CopyIIPC, I don't remember requiring a special controller card? I had it on 5.25" disk and used it. (But maybe there was more to it and I don't remember... it's entirely possible!) And I wasn't thinking of using CopyIIPC - but all this copying disks to my external made me think back to those days when I either tried to copy one of the Sierra games (say like LSL1EGA) that my friend and I went 50/50 on - so I could have my own copy (rather than exchanging ownership every other week or whatever) - I just remember that there was something that CopyIIPC couldn't copy; which made copying the first disk useless.

Out of curiosity; I looked at the Kryoflux and see it's a software... but I don't see hardware, so I am confused how it could give a USB for 5.25"?

[Collector]

It's a floppy controller that connects to your PC via USB.