Presume for a moment we've got a working ALU-like system. Memory is the next problem. Relays are a pain to use for storage. Huge and expensive. The cheapest and most practical form of storage is paper tape, either punched or scan-tron style inked. This form of memory is rather unique, being write-once-read-many (WORM) and infinite in one direction. This is much more restricted than the classic Turing Machine. Can computation be performed on such a medium? |