I don't think ENIAC used acoustic delay storage? Perhaps what you're thinking of is that in the original ENIAC usage, there was no 'program' as we now think of that term; the machine had to be configured (via connecting up computing units with cables) for each separate problem, i.e. more 'configurable' than 'programmable' (at least in the Turing machine sense). Hence the debate over whether it or the Baby was the first 'computer'. Noel