Interesting fix - thanks Thomas! Actually, I did try loading it into monam and stepping through it. Not far into it, the first time it calls Wait() that's all it does - wait.
Now that I think of it, under emulation I've only tried running it on MacUAE so I'll try it on WinUAE too.
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After that nod in the direction of the isup.library, I tried putting it in the actual libs: (duh!) and AZ fired up - but I'm certain it used to find it's isup.lib in its own directory. Anyway, after all that it turns out that AZ isn't tab aware - what a pain! I wonder what the barest minimum of tinkering with monam and a byte editor would be to make it deal with tabs...