Rare pair

[Chasfield]

I just discovered a feature that I had not previously noticed on these calculators. Shifted-f (f,f) invokes "dr", which presumably stands for delete right because it removes the right-most digit, while preserving f mode for the next function call. I assume this must be there as an option for situations where the operator believes the least significant digit to be worthless, or at least better rounded down.

Neither the calculator can handle standard form display or input. You needed to use it like a slide rule and have a notepad to hand for working out your exponents.

The 841 is a miracle of packaging, with a triple decker sandwich of PCBs contained within its small casing. The keys are of double shot construction and the calculator has a wonderful heft to it, once the AAs are installed under the slide out rear cover.