Noob Question 1: Amiga formats

[Peilton]

Hi everybody and please don't shoot me. The answers to my questions are certainly to be found here or easily on the net but I wanted to ask the professionals here about Amiga formats with some explanations if possible.

I've seen that there are some formats for Amiga games, programs, demos, etc. and wanted to ask what they were and how they can be used/loaded.

ADF

I think the original Amiga uses the ADF format and that it can be used with UAE if I’m not mistaken.

LHA

What’s that and how to make it work?

DMS or DMA (can’t remember sorry)

What’s that and how to make it work?

Are there other formats and how and with which programs can they be used?

Feel free to treat me as the biggest noob ever and thanks in advance for your help on this.

[Galahad/FLT]

ADF - Is a plain image of an Amiga formatted disk, much like an ISO is an image of a CD. ADF = Amiga Disk Format

LHA - Is an Amiga archiver that works and does the same job as ZIP

DMS - Disk Masher System, basically images an Amiga disk and compresses each track as it reads the disk to create an archive of the disk. Whereas LHA or ZIP will archive files, lots of Amiga disks have no native AmigaDOS filesystem, so DMS images it as tracks so that you can still copy the information.

[Peilton]

Wow! Thanks a lot Galahad/FLT for your prompt answer

Originally Posted by Galahad/FLT

LHA - Is an Amiga archiver that works and does the same job as ZIP

Does the LHA contain ADF. files or all sort of files and do you need a specific program to "unzip" them (do you need an Amiga to do this or a PC)? And now the greatest noob question for the whole day: why would you use LHA or DMS files exactly (perhaps to have a concrete example on how using it)? Sorry, I really don't know nothing about this. And last but not least are there other formats?

[cosmicfrog]

for lha think zip,rar,ace,7z all compressors

as Galahad said dms packs each track on a disk so as and adf is 900k or so the same dms file could be smaller

[Peilton]

Originally Posted by cosmicfrog

for lha think zip,rar,ace,7z all compressors

as Galahad said dms packs each track on a disk so as and adf is 900k or so the same dms file could be smaller

Thanks cosmicfrog I understand a little better now. So you use this to save memory/place on your HD and/or to make it easier to download several Amiga files? Still one more question: how to "unzip" the files or waht programs are needed?

[Kitty]

You can unarchive lha files in an amiga enviroment or you can use winrar to unpack them on your pc ;-)

[Graham Humphrey]

Originally Posted by Peilton

Thanks cosmicfrog I understand a little better now. So you use this to save memory/place on your HD and/or to make it easier to download several Amiga files? Still one more question: how to "unzip" the files or waht programs are needed?

For LHA files you need the program LHA. Also the Amiga uses LZX also but that's not used as much - you need LZX for them

You can use ZIP and RAR on the Amiga also.

[Peilton]

Originally Posted by Kitty

You can unarchive lha files in an amiga enviroment or you can use winrar to unpack them on your pc ;-)

I love Kitty! No seriuosly thanks a lot Now I really understand! Great! You've all been of so much help to me and so damn fast, thanks a lot!

If someone else would want to complete these informations or add more content that would be very much appreciated as I'm noting down all these comments to make me an Amiga Noob Guide. If it interests somebody I can publish all the answers once I have more information for other beginners like me (of course with credits to all the members who helped). Again, THANKS A LOT!!! YOU?RE THE BEST!!!

And a big thank to Graham Humphrey too for this precious addition I'm really beginning to understand here

[StingRay]

Originally Posted by cosmicfrog

and adf is 900k or so the same dms file could be smaller

Standard ADF is 880k (80*512*11*2=901120 bytes).

Originally Posted by Graham Humphrey

You can use ZIP and RAR on the Amiga also.

I wouldn't really recommend ZIP for Amiga stuff since it doesn't handle protection bits/file comments etc.

[cosmicfrog]

if you say so StingRay though 901120 bytes looks like 900kbytes to me

[skateblind]

Originally Posted by cosmicfrog

if you say so StingRay though 901120 bytes looks like 900kbytes to me

1 kilobyte = 1024 bytes
1024*880 = 901120 bytes

[Angus]

Originally Posted by Peilton

Hi everybody and please don't shoot me. The answers to my questions are certainly to be found here or easily on the net but I wanted to ask the professionals here about Amiga formats with some explanations if possible.

Feel free to treat me as the biggest noob ever and thanks in advance for your help on this.

I can't match the previous posters' technical knowledge but in case it helps here is a basic, practical description.

If you had an Amiga game that only worked from a floppy and you wanted to e-mail it to a friend, you might adf or dms it - and then save the resulting .adf or .dms file to attach to your e-mail. My (limited) understanding of these programs is that they create an exact disk image of the floppy, so that when it is written back to a floppy, the data will be written to exactly the same locations as on the original floppy, which is crucial for some software. Note - these programs are not designed to be able to make copies of protected floppies.

(a bit of a background example)
The WHDLoad guys, when they work their magic to make old Amiga games run from hard drive and compatible with newer machines, sometimes break the game down into its original files, and sometimes use disk images. The disk images will often be called disk.1 disk.2 etc but they are probably just .adf files that could (if you wanted to) be written back to floppy. The patchers (cunning chaps that they are) write a special slave file for the game that enables it to run from you hard drive.

If you had some files to e-mail to a friend - maybe pictures or audio or a game that wasn't reliant on being run from floppy, you could use a program like Lha to compress them into a single .lha file that your friend could then decompress with Lha or a compatible program. I've found it quite useful just as a way of bundling a few files together into a single file regardless of how effective the compression, as its more convenient just e-mailing one large file than lots of little ones.

Note - programs like Lha obviously restore the archived file to its exact original form when it is decompressed. Its not like JPEG compression that uses "lossy" compression where it sheds data from an image to reduce file size at the cost of quality - that would be fatal for a computer program.

[StingRay]

Originally Posted by cosmicfrog

if you say so StingRay though 901120 bytes looks like 900kbytes to me

901120/1024 = 880k

[alexh]

Originally Posted by Peilton

ADF I think the original Amiga uses the ADF format and that it can be used with UAE if I’m not mistaken.

Did ADF exist before the creation of UAE?

I don't remember it back in the day. DMS yes, ADF no.

[Galahad/FLT]

Originally Posted by alexh

Did ADF exist before the creation of UAE?

I don't remember it back in the day. DMS yes, ADF no.

No, people didn't use plain ADF files unless they were using virtual DF0-DF1 drives on their Amigas, and then it wasn't called ADF.

Just a generic term coined by UAE to describe an Amiga disk.

[thomas]

Did ADF exist before the creation of UAE?

No, it did not exist. At that time there was no need to store a uncompressed disk images without any meta-data.

[StingRay]

Not to be nitpicking but disk images DID exist long before UAE. They just weren't called ADF.

[Peilton]

Thanks to StingRay, Angus, Skateblind, alexh, thomas for their precious help and clarifications. Special thanks to Angus who really gave much details here and helping me understand.

I made a little research and 880 k seems to be the right number but coming from a noob like me it doesn't mean much. Hope that you continue here as I'm leraning much in a minimum of time. This forum definitly rocks

[Jonathan Drain]

I used to use DMS a lot for transferring Amiga disks to PC, because if you're copying files over via 720k-formatted PC disks, you need to compress the disk 880K Amiga disk image, and DMS conveniently reads and compresses at the same time. If the disk doesn't compress to under 720k, DMS can also read in two halves. You then turn the DMS file into an ADF file using DMS on under WinUAE.

However, it's probably more convenient to use transdisk (comes with WinUAE) to create ADF files, compress with lha and split those, since lha can be unzipped directly on Windows using WinRAR or 7-Zip. I'll have to look up what software is required to split and combine files.

[Peilton]

Originally Posted by Jonathan Drain

I'll have to look up what software is required to split and combine files.

Thanks a lot and it would be great if you could look up what software is required to split and combine files.

Thanks again and just look down for Jonathan's answer