On Wed, Jul 8, 2020 at 8:46 AM H <agents at meddatainc.com> wrote: > > I believe I mentioned that the UPS has the serial port, the computer thus > has USB. > > yes, but is it 'basic serial UPS' or is it 'enhanced serial UPS' ? the former do NOT use the rx/tx data of the serial port at all, they ONLY use the serial port control signals, and they probably will NOT work with a USB port because they require very specific behavior from those signals at power up and reboot times. the latter DO use the serial data, and may work with USB serial. -- -john r pierce recycling used bits in santa cruz