In almost all cases, you should use the latest beta release of the Saleae software. It can be found here: Saleae Logic Beta Software
However, there are a few reasons you may need to use an older version.
OS X 10.4 & OS X 10.5
The last version of the software to support OS X 10.4 and OS X 10.5 was the Logic software version 1.1.15. You can download the special releases for this here: Legacy software for OSX 10.4 and 10.5
OS X 10.6
The last release of the Saleae software to support OS X 10.6 was 1.1.18, which you can find here: Older Saleae Logic Beta Downloads
CentOs 6.x and older
Due to unknown issues with the QT 5 upgrade, we were unable to maintain support for CentOs 6.x. The last version of our software to use QT 4 was 1.1.34, and a special compatibility release was made that runs on CentOs 6.x, which you can find here: Older Saleae Logic Beta Downloads. Be sure to get the compatibility release.
Other, general notes
If you are using one of the newer products, Logic 4, Logic 8, Logic Pro 8, or Logic Pro 16, you will not be able to use older versions of the software. The only older version you should consider using is if you are on Linux, and the latest software is not working (as in the case of CentOs 6.x). In that case, you should try either the compatibility release of the latest version, or the compatibility release of the 1.1.34 software, as mentioned in the CentOs section.
The original Logic device is supported on all releases, including the original, Windows-only software, versions 1.0.0 through 1.0.34.
The original Logic16 is supported over versions 1.1.14 and newer.
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