NH,
I think this rule about not having an Alpha key is rather outdated - it's really not possible to find any calculators which don't have an Alpha key any more, unless you're going to restrict yourself which can't do much more than +, -, * and /
I don't remember the model number of the calculator I used, but I know it had an Alpha key, as did the calculators which all of my class-mates used. I think that the way the invigilators interpret this rule is that you shouldn't use a calculator which is very obviously programmable, i.e. can store formulae for later use.
FFF
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