@fbry Yeah stacks in subleq is a bit less jumping around than say a register machine, but it's pretty slow. Lambda Calculus style graph reduction is more fun for simple systems to handle stacks, especially if operators are linear. What I linked up top is a queue machine, which is pretty interesting, implementing one in subleq is trickier tho, two pointers at once in a ring-buffer.
@fbry Subleq emulation is fun, here's one I wrote in just a few lines in a pure stack machine language: https://git.sr.ht/~rabbits/uxn/tree/main/item/projects/examples/exercises/subleq.tal