I am using a Casio CM-100 "computer math calc". it has "BIN" "OCT" "DEC" "HEX" keys for single key-switching as well as A-F keys. solar powered. algebraic. time calculations. parens 6-deep, a-shift,shift, rotate, bit-size 1,4,8,16,or 32, only *8* hex digits though. roughly 5 x 2 1/2 x 3/8. well built,…