DMS vs. ADF

[Amiga1992]

Good ole DMS format, nothing else.

Yeah. DMS is old school and it's still used today

[Twistin'Ghost]

And what self respecting scene archive would be complete without a DMS banner - something the adf crowd never gets to experience - the classic old Amiga ASCII/ANSI art from the scene. Which is why I keep all of my DMS files (among other reasons). And anyhow, how hard is it to make an ADF from a DMS file? Either open it up to a disk under emulated WB/AOS or use that PC-DOS tool DMS2ADF.

[RetroMan]

Yup, I would also prefer DMS files but maybe there would be more readers if there would be an extra adf version .... the point is not all Amiga users are able to make an adf out of a dms, sad but true cause I think it´s one of the basics .....

[icycool]

DMS is a pointless abstraction layer between ADF & Disk.
Its also prone to possible corruptions, depending on which DMS proggy you use. almost like using powerpacker..its easy..but error correction..LOL.
Also, most people can use ADF's on emulators and real Amigas..
So the point of making it specifically DMS is just about as useful as saying to invert all the bytes of the image, zip it, lha it, lzx it and then reverse the process to get it back to its real usable format..eg.. ADF

[Twistin'Ghost]

A pointless abstraction layer? Let me remind you that DMS is the archiver we used to spread disks with in the old days, not a tool that was invented in the interim to make emulation more cumbersome.

For me personally, I find using DMS on the Amiga to create disks far more convenient than the additional steps I have to take to convert an adf to an actual disk. I know many will disagree with this, but that's my experience (outside of FMS devices, that is).

And neither DMS nor PowerPacker have given me any more instances of errors inherently. The only PowerPacker files I have had any issues with have been from mutant versions which have been hacked to try to prevent decompression. Maybe they wanted the same level of unreliability as address crunchers? The DMS files that you see corrupted are that way due to being written to disks with sector errors. I have seen this same problem with every other file format, since any file is prone to corruption if written to a bad disk.

The real 'usable format' you speak of is for emulators. But there's still a community out there who prefer using the real thing and I like to think they get a higher priority.

[icycool]

This isn't the old days, and we aren't all limited to 1200bps modems and 200 meg harddrives. There is zero extra work involved in writing an adf to a disk, infact u probably have to type even less, since it doesn't require all the BS options that undms uses.
The only upside to DMS is that it does use compression, and sometimes u will get disks you can't extract.. because the original program didn't encode them properly..thus making the images somewhat useless.
Renaming DMS' isn't an option..the crc's always change if you alter any of the default options for ripping a disk.
Its marginally faster to write out an adf, since its not compressed..
In conclusion (in todays days ) ADF is far superior to DMS as it doesn't require any fucking around... What do you think UAE does when it loads a DMS?.. extracts it to an ADF and uses that, and since many more programs require an ADF format than a DMS one, it makes sense to use what is A) supported more widely & B) much cleaner.
ADF Please

Oh...on a side note to Galahad,
I think a disk mag should really be on a disk since thats what its meant to be. Surely 2 disks of quality info would suffice for 1 issue. Bigger isn't always better (in the computing world ).

[birdy-scc]

it makes sense to use what is A) supported more widely

Yeah, right on!!

I only use emulators so I don't care about the "more worthy"!!

[icycool]

I use both, and I don't care for shitty DMS at ALL!!

[Twistin'Ghost]

Icy, if all you do is emulate, then that works best for you. I am not trying to 'convert' you to DMS and frankly couldn't care less what format you use! You referred a lot to loading files and which programs support this and that, which is something I was not even discussing. I wasn't really even talking about emulation.

And I never claimed this to be the 'old days'. But by that same token, I could throw the same line back at you for using Amiga games software from the 'old days', but I'll at least do you the courtesy of not patronising you, which I should expect in return! If you don't like command line switches, fine. I have no problem with them and if you know your way around AmigaDOS, using aliases can reduce any long command line to a mere keystroke.

You don't seem to have enough knowledge of DMS to be bagging on its compression. I have never in my history of Amiga and DMS usage ever compressed a disk with DMS that I could not decompress (outside of the file having a R/W error from disk. Every DMS I have ever created has been tested back after creating and never once has any compression encoding caused any problems. I'd be interested in any examples you may have to the contrary. If you are referring to DMS2ADF not being able to decode deep compressed DMS files, that is hardly the fault of the Amiga version, is it?

You completely lost me on the renaming DMS's part. You may have to try and translate that one for me, as I could make no sense of that comment. As for the speed of decompressing an ADF over a DMS, DMS also has an option for no compression, should you desire it.

...since many more programs require an ADF format than a DMS one, it makes sense to use what is A) supported more widely...

Then why play Amiga games at all when PC games are supported more widely? Why not always take the high road and follow what the general public decides to use?

[CodyJarrett]

I think that ADF files are better than DMS files. I have found many DMS files that will not decompress on a real Amiga - I convert all DMS archives to ADF files and so find the corrupt ones.

DMS may have been the format of choice in the past, but I wouldn't insist on watching Buster Keaton films on a roll of combustible celluloid film instead of DVD just because that's the original format.

ADF/ADZ files are well supported on real and emulated Amigas alike.

[Twistin'Ghost]

So explain to me what happened when these DMS files would not decompress. Error message? Stopped after a certain track? Didn't recognize the format? You probably need to upgrade past 1.0 of DMS.

I never called DMS the format of choice. And your analogy is extremely skewed, Cody! Try substituting DMS with ARC. DMS was the last developed/supported disk archiver then and is still used today, which you cannot claim about Buster Keaton films on combustible celluloid. Nice try, but the format is not that primitive just because you don't prefer it!

As for support, I have had as much failure with gzip decompression as with xdms.

[CodyJarrett]

We've had this discussion before... Let's leave it at personal preference before it turns nasty!

[icycool]

Ok, just found this thread thru idle searching.. strange it should be in general discussion when it is amiga related.. amiga scene perhaps?.
Now, my reference to 'todays days' was to point out that DMS was adequate back then (the old days), and with its compression, a good tool for modemtraders alike.
I am a real amiga user, i have 4 of them here, but i will not use DMS out of preference on any of them if an ADF exists. And I will certainly never encode a DMS these days, simply coz the benefits gained by the format are outweighed by the hassle of use.
If you like to use the format Twistin' then by all means get your ADF's to your amiga and encode them, and decode them next time you want to check for matches in the TOSEC dats..

You completely lost me on the renaming DMS's part.

To explain it simply, there will NEVER EVER be a DMS dat, and if some trollop does decide to make one, see how long before the data is ripped straight into an ADF dat.
As Cody pointed out, there are lots of BAD dms files out there, and obviously created by a bad DMS program. Now thats fine and all but unfortunately u can't get the data out of them. If it were an ADF of the right length, most of the data would still be there, just a few scrambled sectors here and there. I prefer data integrity over non-perfect(not 100% all the time) compression and would prefer the odds of a harddrive failing to cause bad data over the reliablity i have experienced with DMS. A long time ago, I used DMS2.03 or similar to encode a bunch of disks. I assumed it all went fine until one day I wanted that data back on physical media..some failed..which pissed me off to the extent of writing a sector disk ripper which creates an ADF. As they say.. once baked..twice fried.

[mr_0rga5m]

As Cody pointed out, there are lots of BAD dms files out there, and obviously created by a bad DMS program.

Did you guys never take the time to use the verify etc.. when creating DMS files?.

I personally have only seen a coupla 'bad' dms's in the past .. and when testing the dms file the output would say "r/w errors reported when creating dms file", IE: the fool who created it didnt care to read the results outputted when creating so the end product was spread bad.

A bad workman always blames his tool(s). ;P

I personally used to love seeing the ascii msg's output ... the *hidden* msg's in the DMS were a fun part of the whole 'scene' thing.

I still delight in seeing GOOD ascii .nfo and .diz's from the olde () days to present days.

[Codetapper]

OK guys, let me add my 2c to this discussion. Firstly I would like to say that every single version of DMS I have seen is bugged:

- Some games will apparently READ correctly, produce a DMS file. When you DMS TEST NameOfGame.dms it says no problem found. Then you unpack it and it says CRC error and aborts. Lame.

- Most versions of DMS have the CMODE options stuffed. If you choose CMODE HEAVY1 for example it will either crash or say that isn't supported (most versions, not all).

- Some games will apparently READ correctly, but if you convert the DMS file back to ADF and compare with the original, the files are DIFFERENT! This is not due to a dodgy disk as I have tested lots of these with FMS devices which cannot have errors. An example of this is Superfrog disk 3 cracked by Crystal. With one of the standard compression options (can't remember which) you cannot DMS the disk and get the same data as the crack. Usually I have found the final few tradks contain byte differences (track 78-79 usually).

In DMS' defence:

- It is the only format which allows you to distribute patches, a trainer or AGA fix of a couple of tracks.

- It compresses the tracks so even A500 owners without much memory can use it.

- DMS tools like DMSSplit exist to put a large 900k DMS archive into 2 pieces to give to your poor HD-less A500 owners.

- It is from the old scene days!

Now I will say that my entire collection of disk images are all stored in DMS format. Why? Purely because that is what the collection started off as and I can distribute patches/AGA fixes in that format. The main reason though is I can guarantee my DMS archives are 100% perfect.

How?

If I want to convert any ADF file or floppy disk to DMS, I use DIC to read the disk as an ADF file. Then I use a utility I wrote to unpack the ADF to FF0:, run DMS to pack the archive, then it calls DiskWiz to unpack the FF0: archive back to an ADF and compares with the original ADF:

- If it matches, it deletes the original ADF and I have a 100% guaranteed exact duplicate DMS archive of the disk in place of the ADF. This is 100% safe as it has been unpacked by DiskWiz and matches byte for byte the original ADF.

- If it fails, it prints out an error message and cleans up the files LEAVING the original ADF so I know that wouldn't convert safely.

If anyone is interested in this utility I will try and clean it up (it's a bit messy) but it works for me and I can personally attest to having seen at least 20 disks in my time which DMS thought were good. In the old days I would now have a corrupt DMS archive and think that the game may have been a dud crack or missing features etc...

So there you go, DMS is bugged (but I still use it!)

PS: I request all original suppliers to avoid DMS when sending me stuff as the time to make an ADF and LHA/LZX it is usually faster, compresses better and I can be safe knowing that the ADF is 100% ok.

PPS: I find all emulators are crap at handling DMS archives anyway, they fire up XDMS to unpack it and then it doesn't put the unpacked ADF into the floppy drive anyway! What am I doing wrong?

[Twistin'Ghost]

Originally posted by |cy[ool
If you like to use the format Twistin' then by all means get your ADF's to your amiga and encode them, and decode them next time you want to check for matches in the TOSEC dats..

I never indicated anywhere that I was making DMS files out of ADF files. I merely suggested that creating a disk from a DMS file was easier for me than from an ADF. You and Cody sure are using remote, extreme references, but I fail to understand why the arguementive attitude. Nor did I ever say anything about TOSEC matching. Nor did I indicate DMS as a preferred tool for emulation, which is really what the TOSEC dats are for (since those long filenames won't work on a real Amiga!) Icy, as much as you talk about the inconvenience of DMS on a real Amiga, you seem to embrace TOSEC. I see a double standard here. And how many times have you seen me post DMS files to the ADF Zone? Don't make me out to be some fanatical DMS zealot who is denouncing ADF's!

Originally posted by |cy[ool
To explain it simply, there will NEVER EVER be a DMS dat, and if some trollop does decide to make one, see how long before the data is ripped straight into an ADF dat.

Again, you seem to fall back to emulation from real Amiga for convenience. As I have stated several times, I am talking about on a REAL AMIGA! Why would a real Amiga need a dat of any kind? For someone with four Amigas, you seem to think only in terms of your emulation!

Originally posted by |cy[ool
As Cody pointed out, there are lots of BAD dms files out there, and obviously created by a bad DMS program
[...]
A long time ago, I used DMS2.03 or similar to encode a bunch of disks. I assumed it all went fine until one day I wanted that data back on physical media..some failed..which pissed me off to the extent of writing a sector disk ripper which creates an ADF.

Cody did a lesser version of what you did; he generalized that he'd had DMS files go bad. There were updates of DMS past 2.03, including a scene version, which is the version I use. I have very little recollection of the original version(s) of DMS, I only know that the scene version was infinitely superior (not that I have any technical info to back that up...)

In closing, I am just trying to make clear that I am not trying to preach DMS here. I am stating that I like using it on a real Amiga and that the only problems I have experienced with (the version I am using) is from files with read/write disk errors, which is not the fault of the compressor.

Codetapper, which version of DMS are you using? One possible reason for getting a different crc from a disk that has been undms'd is the nozero switch. I once took a disk full of iff pics, deleted them all, then DMS'd the disk. Without the nozero switch, the dms file was tiny. Then I did the same with the nozero switch on and the DMS file (of the empty disk) was huge. It's obvious why this was the case, but my point is that I have seen some disks which are simply DOS disks that are archived with the NOZERO option, so more useless data is being stored. The way to eliminate this is to re-dms without the switch so that that information isn't archived. Surely this will produce different crc values.

[7-Zark-7]

Okay to begin with, I'll make my personal preference clear-ADF. As I usally play games on WinUAE, it's the easiest to use, with no hassles saving etc.

I'm sure this has been raised elsewhere before, but to save on the ADF file space, I would love to see a MAME-like feature which allowed you to load up your zip files directly in WinUAE.

[Codetapper]

Originally posted by Twistin'Ghost
Codetapper, which version of DMS are you using? One possible reason for getting a different crc from a disk that has been undms'd is the nozero switch. I once took a disk full of iff pics, deleted them all, then DMS'd the disk. Without the nozero switch, the dms file was tiny. Then I did the same with the nozero switch on and the DMS file (of the empty disk) was huge. It's obvious why this was the case, but my point is that I have seen some disks which are simply DOS disks that are archived with the NOZERO option, so more useless data is being stored. The way to eliminate this is to re-dms without the switch so that that information isn't archived. Surely this will produce different crc values.

I have tried ALL DMS versions - from the original 1.11, 1.12, the GUI versions, 2, 2.05, 2.20r (the LSD one), 2.31r etc. They all have some/all of the bugs I mentioned.

Regarding the NoZero flag, I have tried that - The NOVAL and NOZERO flags shouldn't affect NDOS disks as the bitmap is invalid so DMS will pack up the whole disk. I always set DMS to simply archive the disk and not make guesses about what is on it (as I am smarter than it And yes, it would produce different CRC's depending on that switch.

The only way I ever managed to convert my Superfrog disk 3 back to a working DMS was to read tracks 0-78, then APPEND track 79 - which seemed to work! Reading 0-79 caused the final track to be different from the disk version.

[RetroMan]

Hmmm, which one got minor bugs then ? And would someone please post that Version to the Zone ?