i had a casio (i think) calculator with a fold-out keyboard with all the hex digits (A-F) and the boolean operators. it would take input in binary, and hex, but not octal. my then gf bought it me as a bday present. appreciated, but not much used as at the time i could do all the binary/hex/decimal conversions in my head, not to mention converting them into z80 opcodes.

sadly, no more - too old and forgetful

this would have been about 1984