hp-80 behaving badly


I have an HP-80 that's working perfectly except for one strange behaviour: any attempt to calculate using the top 5 keys (e.g., present value) causes the display to go blank until the calculator is turned off and then on. The calculator accepts inputs for each key, it just won't calculate the answer when the key for the dependent variable is pressed.

My other HP-80 works just fine using the same inputs. Any idea what's happening?

Edited: 3 June 2010, 4:02 p.m.


The HP-80 with the strange behavior is seeking more of your attention???? You know, like kids who misbehave??




Maybe it's jealous of the other HP calculators; however, I expect one of the ROMs has gone south. Playing with it more, I find that all the financial algorithms don't work; the normal math functions work fine.

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