Need to run at least 7 (maybe more) samplers from a single computer port. Would like to do it from ttyS1 (com2) but am more familiar with using an ADC off of parallel (printer} port but cannot find enough I/O lines (/registers) to do it (via bit banging) with the serial port. Any help on this part?? Am intending to start with just 1, 8-bit chip off of the parallel port. Problem is this: some devices will be serviced every minute others at 5, 10, 15, 20, 30, and/or 60 minute intervals. The selected device will be fed to the ADC via this multiplexer. Now I think I know the difference between synch and asynch but with multiplexer chips I am unsure what that means exactly. Does it mean that if the chip is synchronous that the clock must be strobed via a separate clock on a regular basis? I expect to select the channel on the appropriate chip (if more than 1) feed the ADC by strobbing the bits off of the ADC then go to the next device. Can someone clearify the synchronous vs asynchronous multiplexer question for me??