Bad firmware zip file for Mac OS Fab ISP English instructions
Under this page: http://fabacademy.org/2019/docs/FabAcademy-Tutorials/week04_electronic_production/fabisp.html
The Firmware zip file under the Mac OS instructions is bad (linked like this "FabISP Firmware (right click save as)"); it cannot be opened successfully on Mac, listed as "invalid" by windows. This is the offending file:
https://github.com/Academany/FabAcademany-Resources/blob/master/files/firmware_44.zip
Later in the Windows instructions, there is a good copy of the firmware linked ("5. Download the FabISP Firmware"). Here is the good file: http://academy.cba.mit.edu/classes/embedded_programming/firmware.zip
Probably the firmware_44.zip file should just be replaced with a firmware zip file that works (e.g. the CBA version), but alternately, the link could just be changed to the cba link.
Thanks, Greg