What has the DM41 extra over the HP42s?

[Thomas Okken]

It could also catch everything except Shift-EXIT. That way, no tricky work-arounds would be needed to break out of buggy or malicious loops, you could still handle EXIT and R/S in a customized manner, and Shift-EXIT isn't likely to clash with anything else people might want to use that key combination for. And it's something that breaks out of the original GETKEY as well — though not out of the current Free42 GETKEY, due to the silly bug I alluded to before.