I have one of these (although the display on mine is not quite as bright). The HP9100A had register operations and logical and scientific functions with maximums of 16 storage registers and 196 program steps. Core store remembers them nicely. This was the only desk top calculator in a lab of 60 engineers when I started working there in 1972. It sat on a trolley with a little flag on a telescopic aerial so you could spot who had it in the open plan maze.
Peter
