Tired of not getting the enchantments you want? This state of the art enchanting room lets you add or subtract bookshelves at the press of a button.

A bit more explanation. This is a solution to a problem most players have no idea they have. Enchantments seem random but they can be influenced by the number of bookshelves in proximity to the enchantment table. Generally better and higher level enchantments happen with more bookshelves up to 15. So typical library construction is a corner or circle of 15 bookshelves. But you might be missing out on good enchantments that don't require the maximum bookshelves. Maybe you could get a silk touch without unbreaking for instance if you only use 10 bookshelves. So I created a push button system that lets you specify the exact number of bookshelves you want.

This latest version is a do over and doesn't have as much functionality as the one from 2019. You can unlock the old functionality if you understand a little of the operating principles. The device is a 4 bit binary counter.

My previous attempts at an enchanting library relied on solid state boolean circuits. This was spaghetti that was very tricky to implement and took ages to bug fix. Then I watched an old video by AntVenom about binary counters that rely on the block drop exploit. When a sticky piston receives a fast pulse it may extend and retract its piston so quickly that it can "pick up" and "drop" any movable block. A block drop piston is an excellent memory toggle. I implemented this exploit both with the 4 bits of memory and also with the bookshelves. The whole system runs on fast pulses without any steady state logic, with the sort of exception of a reset.

A long pulse, such as from a button, will toggle the memory and output to 1111 then 0000 when the pulse is over. In the new version I haven't included a reset button. The included button on the blue wire is for increments. The pulse from that button goes through a piston filter. The piston extends when powered witch cuts off the signal. The piston retracts when the button pulse ends so it doesn't drop its block. Another easy way to generate a fast pulse is with an observer. Observers with trapdoors on their face make awesome toggle switches for a pulse operated toggle. I connected some observers to the bit channels of the device. You might want the ability to toggle the bits individually. If you have an idea of the number of bookshelves you need you can use the bit toggles to dial it in. This is probably faster than incrementing your way through.

Finally I included subtraction mode. This green wire, when pulsed, will toggle every bit of the memory without affecting output. The value in memory will be inverted. Incrementing memory is now equivalent to decrementing output. With the device in addition mode memory and output are equal. A memory state of 0100 is 4 bookshelves. When subtraction mode is toggled you still have 4 bookshelves but now memory store 1011 (11 in decimal). Adding one to memory results in 1100 (12 in decimal) but output now changes to 0011 which is 3 bookshelves.

Anyways I hope you can enjoy this and maybe learn a little binary. That's all for now