Complete PC MS-DOS Collection DOSCenter Documentation
From Underground Gamer
(initial docs, much more to do. --hargle 05:00, 30 December 2009 (CET))
DOSCenter - use this to manage your DOS collection.
The idea behind DOSCenter (DC) is to create a tool that not only allows you to manipulate your collection of DOS games, but to also scan and compare your zip files against the known database, as generated by The DOS Collection (TDC).
TDC is a group of dedicated individuals who are trying to locate, organize, and name every DOS game ever created. There are an estimated 11,000 DOS games in the world, and this tool can help you see how your collection stacks up.
DOSCenter was designed to help get your zip files in shape.
You probably have a folder or two of old DOS games, perhaps the zip files are named as something recognizable, perhaps named something like P2DB1.ZIP or even AWTYTHG.ZIP. You may have remembered what those zip files were 10 years ago, but by now, they are likely unrecognizable. DOSCenter will assist you in sorting, renaming, merging, viewing, and overall managing your DOS games collection.
DOSCenter as a renaming tool
DOSCenter can help rename files in 2 ways:
i) Rename by hand:
1. Browse to you zips folder. 2. 2x click on any zip file and you'll see the contents of the zip on the right-hand pane. 3. 2x click on one of those files and it'll display the file in an editor. 4. You can then copy text from that editor into the clipboard (I'm thinking you'd examine a file_id.diz, a readme.txt or perhaps a .doc file) 5. right click on the zip file name on the left-hand pane and select "rename from clipboard" 6. a new filename dialog will appear with the text copied from the clipboard which you can edit. When you press enter, the .zip filename will be renamed.
ii) Rename by .dat file
1. click the "load .dat" button and load in the .dat file released with the complete DOS collection 1981-1989 torrent: http://pc.nugnugnug.com/DOSCenter 2. check the "auto scan zips against .dat file" checkbox and browse to your folder of .zips 3. wait. DOSCenter is comparing the CRCs of your zip files against known CRCs stored in the .dat file. 4. If any matches of CRCs are made, DOSCenter will suggest a new filename in column 2 of the left-hand pane. 5. Right click any file and select "rename" and the rename window will show you the suggested filename.
Now for the sucky part:
DOSCenter can only deal with .zip files created with pkzip 2.0 or higher. That means that any .zip that uses the old "implode" method of compression will not be readable by the program. It will still be able to get the CRC of the files, but DOSCenter is unable to unzip and display any files. If you run into this problem, I suggest using winRAR's "convert archive" tool to refresh your entire folder of zip files to a newer compression method. WinRAR can do the conversion in bulk, so it's not that bad of a thing to do, plus you'll get smaller .zip files in the process.
Q) Doesn't ROMCenter do this too? A) Yes, however, ROMCenter has issues with multiple games using the same file. For example, many early basic games were released with gwbasic.exe. ROMCenter will think that the 1st game it finds in the .dat file that matches CRCs with gwbasic.exe is the proper name of the game, it doesn't actually look at the .bas file included. You'll see that ROMCenter is trying to rename a lot of games to the same .zip filename. DOSCenter tries to be a bit smarter about that and looks at the entire .zip file and builds a "best match" table from the hits it locates in the .dat file.
ROMCenter also wants to delete "useless" files from inside your zips. If you don't disable these features, you can trash your collection very quickly. DOSCenter only renames the .zip file itself- it does not touch anything inside the .zip file.
Quick start:
well, there's no hard rules as to what needs to be examined and what doesn't, which is why it's so hard to describe how to do the work. However, here's my guidelines:
1) Go into DC and under settings, scoring setup, make sure you have a file_id.diz entry in that list. I think that was already the default, but just in case, add it in there (right click in the window and add new, don't add a CRC to it) and also make sure that "ignore files less than" is checked, with something like 50 bytes is set.
What that does is makes DC skip over file_id.diz, since that is a file that we generate for the dos collection before releasing the torrent. Obviously, games you download from the net will very likely not have the same file_id.diz as we generated, so there is no point in checking that file. Likewise with the "files under xxx bytes" skipping. this makes DC ignore any file, typically like a high score file, that is below a certain size. This gets less and less important as we get into bigger and bigger games, but for these 80s games, you can ignore a lot of junk this way.
2) now scan the folder you want to examine, sort the finished list by score.
3) scores: scores that are > 100 means that that game has all the files that our .dat file has, and more. (1 point per additional file I believe) This could be good, could be bad. If the additional files are savegames or documentation, or BBS ads, or misc cruff that we don't need, then we're not missing anything important. (documentation should be removed from the game and zipped separately as a companion torrent, unless the game was actually released with the documentation, like lots of shareware games are) lots of times people put PDF scans of the original docs in the zips. we want to move that stuff elsewhere. It's still good stuff, do don't delete it, just move it into another zip and name it "game name (year)(publisher) [documentation].zip"
4) On the main DC window, in the bottom left, click on "hide matching CRCs"
5) 2x click on a game on the left side window that has a score > 100 (if there are any) see what shows up in the right side window. If there are files that are important (.exe files, .dat files, files larger than 1k or so) those might be important.
Color Key:
Left Side:
file is unscanned = black
file is perfect, contents and name and exact matches = green.
file is recognized, zip filename is wrong = brown
file is recognized, missing some files = red
file is recognized, additional files = purple
both missing and extra files = blue
Right side (inside the zip):
file is unknown = black
file is missing = red
file is ignored = gray
filename/CRC mismatch = brown
file is perfect = green
Scoring mechanism – Every file inside the zip is scanned against the .dat file, looking for matches to the file’s CRC, and awarded a points per file. The highest score is the file that DC thinks your zip is.
The score is calculated based on the number of points accumulated by the files inside the zip versus the number of files in the .dat entry, then normalized to a 100 value.
A score of 100 means that the target zip file exactly matches the best .dat file entry. Every file in the zip exactly matches the CRC and filename as provided by the .dat. Yay!
A score greater than 100 means that the target zip file matches the best .dat entry, but there were additional files also included in the zip that the .dat file has no record of. These might be BBS ads, configuration files, documentation files, or other items which should be stripped from the zip file, or it may be files such as additional video mode files or files which *should* be included. (and our .dat file updated) The only way to know is to 2x click on the file itself and examine what the additional files are.
A score lower than 100 means that the target zip file has less files than the .dat file has record of. It may be missing critical files required by the game. Again, the only way to know is to 2x click on the file and get a listing of the zip. Files the zip is missing are displayed in red on the right hand side of the screen. Also again here it is possible that the .dat file has extra stuff that it shouldn't, so don't be too quick to think your zip is incomplete. Only a careful eye will know for sure.
A score between 85 and 99 typically means a slightly alternate version of a known game. If you 2x click on the file and get the file list, and see that “game.exe” is displayed in black, and “game.exe” is also listed in red with a “-missing-“ tag, then it typically means the file has slightly different file contents (typically a different crack method or different version of the game itself).
A low score (typically below 85) usually means that either this is a game that DC has no record of whatsoever, or the game is a very different version of a known game, and only certain files matched the database, or were complete false positives. (sometimes font files or sound drivers are duplicated between different games and will cause a false reading.)
In the left-side file list, you will see 4 columns on the rightmost side. Score, ==, xx, ??. These are the file’s score from 0-100+, the number of exact matches (==), the number of files your zip is missing (xx) and the number of files that DC has no idea what they are (??).
These columns are there for informational purposes only; feel free to hide them by sliding them off the visible viewing area. Occasionally it’s useful to sort by those columns though, often to find zips that are way different than that .dat file describes.
The Zip viewer has several tools available to it. If you 2x click a file inside the (right side) window, DC will bring up a file viewer. Depending on the type of file it is, the display will either be in hexadecimal or a simple text viewer. The hex viewer also has a strings function that can pull out any text based string inside a data file. This can be useful for locating (c) years, author strings, or hidden messages inside the game!
You can also select file(s) and delete them with the delete key or a right click menu. likewise, you can drag-n-drop files from explorer into the file list to add them to the zip. Folders don't work at this time.
DC also has a file comparison utility (which is a little rough) that can allow you to compare 2 files from 2 different zip files. It'll attempt to find the correct zip file to compare to based off the suggested/scanned zip file in the collection. if it can't be located, you'll get a file browser to locate the zip. DC will then show a file dif view and allow you to compare the 2 files. This can be useful to see hacks and even differences in cracks, if you're good at examining hex opcodes.
