Changing Of The Guard

[bshoring]

I believe the first HP with guard digits was the HP-91 printing scientific, with 3 guard digits. It would make sense to me that any calcs that came out after it, including the late Woodstock, and all that followed would likely have those guard digits.

Hopefully someone can verify if that's the case. As best I can tell, Spice, Nut and Voyager calcs had about the same level of accuracy.

Bob