What is the: Bus 004 Device 008: ID 0764:0501 Cyber Power System, Inc. CP1500 AVR UPS
device?
That's my backup power supply.
Should /dev/ttyUSB0 pop up when I plug the adapter into the usb port, even before I connect anything to the serial port of the cable?
Yes.
What happens in the kernel log when you plug the device into the system?
Try doing: dmesg -c # plug in the adapter now dmesg to just see the log messages for that, and not the whole kernel boot log.
2) root:~> dmesg -c #plug-in adapter 3) root:~> dmesg Absolutely nothing. I also did tail -f /var/log/messages then plugged in the adapter, and again, everything seems dead. The USB port is ok, because other devices (e.g. the Fushicai video grabber) do work.
If the adapter is not supported, can I write a driver for it? I'll be happy to, with a little guidance to get me started. Any pointers?
Odds are the device id just needs to be added to an existing driver as I do not know of any "new" usb-serial converter chips that Linux does not already support.
Oh, one more thing. Reading about these converters, I saw many use an ftdi chip, so I did modprobed ftdi_elan and ftdi_sio: 7) root:~> lsmod | grep ftdi ftdi_elan 36689 0 ftdi_sio 48770 0 In fact, the dmesg above was with the ftdi modules loaded.