The LZX Page (original) (raw)

Authors : Jonathan Forbes and Tomi Poutanen

Copyright : Data Compression Technologies

Last version : 1.21 (1995)

How does it work?
LZX uses a compact way of encoding large match offsets. The Amiga implementation includes file merging, where data are grouped into large blocks, instead of being individually compressed.

Read the original LZX v1.21r Documentation (1995) in html format.

Download the LX executable (for Amiga) here : you'll be able to unpack all the downloadable files.

Questions about LZX? This is the FAQ area.

1 - I have corrupted datas during an extraction operation.
The versions for 68020 and 68040 are not so reliable when you want to archive a lot of small files: you may have corrupted datas in the archive. But LZX won't report the bug during the archiving operation. It will report the bug in the test, or on an extraction operation.
Solution : use the 68000 version to archive your files if the 020 or 040 don't work.

2 - I have the message "LZX: Error writing to disk; disk full?"
It's because empty directories have been archived (sometimes, you may need to do this). This message is not important, just ignore it, because at the end, the extraction will be successfull..."All files ok." and the empty directories will have been created successfully.

3 - I see a problem in the date attributes in the extracted files.
LZX original version doesn't support dates after 2000.
Solution : download and use the 1.21 Y2K fixed version.

4 - I can't use the "-9" option (maximum compression) with the 68000 version.
It's normal, this feature is not implemented in this version (read this page from the original documentation).

5 - 2 patches have fixed the Y2K bug. Which one should I use?
It depends on your way to use LZX. I've done the test and click here to read the results.

6 - Is there a link between UnLZX2 and LZX-2?
No. UnLZX2 is just a new unarchiver for the first LZX.

7 - Where can I find technical informations about LZX?
Go to the Microsoft's page about the .CAB format. Then download the file "cab-sdk.exe" (it's a self-extracting program for PC). If you have an Amiga, use the XAD system on this file: it will unpack it. Place the file in RAM: and type in a CLI window:
xadunfile ram:cab-sdk.exe ram:
After the extraction, you'll see a "DOCS" directory, then read the file "LZXFMT.DOC" (.RTF format). You'll have almost all the secrets of the LZX compression.

8 - Is there any source code of the old LZX software which is now freeware available?
No, sorry, the source to LZX was never released. But you can get the specs for the LZX-2 file format from the Microsoft CAB SDK from Microsoft's web site. There is also a Java implementation of LZX-2 in the class com.ms.util.cab in the Microsoft AFC (Application Foundation Classes for Java).