Another alternative, one that is extremely difficult due to the electronics, is to evenly match the I/O device with the processor. The computer could input a byte from the data port, store it into memory and then execute a fixed number of NOP instructions before going back and getting the next byte. Why this doesn't work too well is because it is hard to synchronize the tape drive with the CPU -- get them started at exactly the same time. And there might be some sort of unevenness in the speed of the tape drive, perhaps due to unevenness in the speed of the tape motor. Since most CPUs are vastly faster than 8 times the speed of a peripheral, it makes more sense to use control signals like those we introduced above.