My single-key buzzer from buzzers.com works fine on Windows but the Mac fails to recognize it. The prompt said press the key to the right of the left shift key so I programmed it to generate 'z' ... on one Mac it accepted it but generated 'a' ... on another it failed to recognize. I think the scan codes are standard, e.g. 'a' = 04 'z' = 1d' etc.