I need to build a type of memory that can hold 256 bits of memory, including on's and off's but it seems like the only way to do it would be with hundreds of RSNOR latches and I was just wondering if there is a more compact way to do it, preferably as quick and simple as possible too. Also if it is possible for it to make it store four different groups of memory, each 256 bits large, that'd be perfect. I think I saw a video with what I want but it still seems impossible.
As BlaXspirit points out, locked repeaters is a latch suitable for memory (it's a gated D latch), and since they only take up a few blocks, they're as compact as you're going to get it.
Another alternative might be an OR combo lock though.