Selectable Output -- Solved

[LoGaL]

i was about to suggest some digital circuit but seems you sorted that out

 

[kiwiCptn]

We solved it people!

Credit to @Henry Link . The bookshelf turtle looks at its signal and puts the corresponding number of blocks in the chest.
The PRC turtle looks into its (same) chest and outputs the corresponding signal. This happens every 0.5 seconds (which is fine).
There's some 'defensive programming' involved (ie some ifs) to cover the 0th case. The stack becomes nil, etc.

 

[GamerwithnoGame]

We solved it people!
View attachment 32852
Credit to @Henry Link . The bookshelf turtle looks at its signal and puts the corresponding number of blocks in the chest.
The PRC turtle looks into its (same) chest and outputs the corresponding signal. This happens every 0.5 seconds (which is fine).
There's some 'defensive programming' involved (ie some ifs) to cover the 0th case. The stack becomes nil, etc.

Nice! Really nice! I'm glad you solved it, that's been really interesting to find out - I'm really glad the RedNet worked for you too!