yes of course, you can implement it using transistors, after all, all ICs are composed of transistors.
I was trying to find a way not to use so many transistors to "simulate" the behaviour of the chip.
What I am inerested in, is the functionalyti of the circuit. i.e. to set an output on the first key press, then to set another output on the second key press etc...
Have you seen any similar functionality schematic?
I could do it using just a rotary switch, but I like the more electronic way..