the button idea is absolutely possible like this:
inside the pulse chip:
the rest of the chips you should be able to find by just searching up their names
the multi-wire would be a lifesaver for me. it's possible to make a thing that uses a clock to encode a bunch of signals on one wire
and a synced clock on the receiving end to continously update the signals but the more signals on one wire the longer the potential delay before it updates on the receiving end
in this approach each bit will update every 16 frames, it's also possible to make a 4-bit multi-wire that updates every 4 frames, any other number of bits would be sub-optimal since the clock has 4 settings: every 4 frames, every 16 frames, every half second and every 1 second. also in case you can't see from the images each pulse chip activates the pulse chip below it
here's the modded version i made for more space: https://www.mediafire.com/file/nrry9bvscl2ki8f/DLS_%2528modded%2529.rar/file
W A S D - move
E - zoom in
Q - zoom out
i don't have any ideas for a screen but i'll definately post about it if i come up with something
an HDD is unfortunately impossible without modding the game, if you open one of the JSON files that store the chips, you can see that it only stores the subchips, their positions and all of the wire connections