Clicking on the .exe files will not unzip or copy the downloaded files on a Mac. The following work-around does the job:

1) After downloading, drag-drop each .exe file onto Stuffit Expander (v 6.0 or later). It’a available online at n/c from Alladin Systems. It will make a new .zip file and decompress it into a folder or .pcm file.
The “manualeStandardEng.exe” is decompressed into a .pdf file, and has the same info as the website insructions and update.
2) Copy the files from the Standard folder onto a floppy, so you can use it to update the system on the SD1.
3) Follow the rest of the website instructions, either using the KetronFT program (the fastest way) or copying the files to floppies.
Remember to set the SD1 Utility to PC, not Mac, when using the KetronFT program.

I hope this helps.
Don Kane