HHC2021 Bob's Calculator Challenge

[rprosperi]

I'm glad you liked the Challenge J-F, it took a couple years to assemble those odd questions.

Regarding the HP-22S, at least one of the late, stepped-bezel style clearly existed, but only in prototype form, thus not meeting the criteria of being a 'production model'.

Regarding the 71B's support of -0.00, I had simply forgotten this was supported. which I've since easily confirmed (try 2 * -0.00). Rather embarrassing for a long-time 71B user and apparently not much of an expert...

I'm intrigued about your comments on the HP-45, I need to try this today. I suppose a display of -0.00 under the default display setting of FIX 2 for values such as -0.001 should technically qualify as a valid answer, cases I had not considered. It's all about the rules... :-)