Combine split .dms files?
 

Downloaded some megademos from ftp and most of them are split in half (to fit on PC floppys I guess). Stupid question maybe, but how do I combine them to one .dms to run in WinUAE? Mounting each half in DF0: and DF1: in WinUAE and copy tracks with X-Copy or something would take too much time I think ;)

Does this work: copy /b first.dms+second.dms final.dms?

copy /b is the method I always use for joining split .dms files.

Strange that this works for you. :shocked
I always depack the two dms parts to adf-images and then join the adf files.
If you join two dms files you have the header of the second dms-file added in the middle of the joined file and at least the popular XDMS cannot depack those files!
Just tested: original amiga DMS can depack those joined dms files, seems it ignores the second header information. Dunno about Winuae's dms handling....

Did the copy /b, got a file of the right size, WinUAE guru'd when I opened it.

Anyone have a link to a clear and concise description of the .dms format? Might do a quick PC utility... ;)

Found a description here:

http://lclevy.club.fr/amiga/DMS.txt

If I do a utility I will limit it to two .dms files, only use track info to see if they are contiguous and don't overlap, and I won't interpret the track data at all, just form a new file with a (modified) single header.

I'll see if I can do it tonight... meanwhile, anyone see a problem with that method?

Hmm, might get trouble with unpacked/packed CRC, especially unpacked CRC since I don't want to unpack it... Is it a simple 16-bit sum, so I can add the words from the respective .dms files to join? But it's probably a "proper" CRC though, is it the 16-bit IBM CRC, or what flavor. Argh. :(

Why not just insert a blank disk, unpack the first DMS to it (using DMS of course), then unpack the second DMS and now you have the complete ADF? It won't matter if tracks overlap or anything.

Codetapper is right. It's very easy, no tool coding needed. You can also use xdms to unpack both splitted dms files and then a simple copy /b later you have what you want...
Dms used the x^16+x^15+x^2+1 polynom as CRC-16 for the headers and for all tracks.

CodeTapper, Adderly, sure - but then I have to do that for every megademo I've downloaded from scene.org... As a programmer I like niftier solutions, if possible ;) I mean, there are tons of split archives out there...
Right, so it's not possible to combine the checksums without interpreting the compressed or uncompressed data. Gah. :)

You could make a batch file for using xdms:
Then you can write
(without endings!) for joining part1.dms and part2.dms to final.adf.

Or you can replace
with
in pfile.c of the xdms sources and then you can use the batch file

This way you can use it with endings or without.

I remember asking this question a few years back.. AFAIR never really got a decent answer back then.. maybe this time..?

Thor: Sweet. Might do a simple shell for it that does a search for split archives in the directory of choice and turns them all into .adfs. :)

@Phiber: well Heikki aka "shd" has taken over xDMS development from Andre.
=> http://zakalwe.fi/~shd/foss/xdms/

He's been absent for ages now, but if anyone is interested in adding this, it's him - Andre doesn't have time for that stuff anymore.

Also see this thread
http://eab.abime.net/showthread.php?t=25018

You can use ADF Workshop

There's a command called "Merge some files..." which can be used to put together the splitted .dms