I think HyperCard and AppleScript were the only programming environments installed on those machines, and he was a big PC proponent, so I don't think he had a M

I think HyperCard and AppleScript were the only programming environments installed on those machines, and he was a big PC proponent, so I don't think he had a Mac at home. I don't think he used any specialized tools, and I don't think he was using AppleScript to bit-bang binaries into the network driver's region of memory. That does remind me of a story I heard, that the zero page was mapped, and the first 64 bits of the zero page were initialized to zero at startup. So, if you derefernced or duble-dereferenced NULL as an *int, *float, *double, **int, **float, **double, etc., there would be no error and you'd get 0 or 0.0. Apparently, the Excel port for Macs had quite a few NULL double-dereferences, either intentionally taking advantage of this "feature" or by accident. Many developers installed a system extension that would set the first 32 bits of memory to a value larger than the amount of installed memory, guaranteeing an error if NULL were double-dereferenced.*