On Mon, Feb 22, 2021 at 09:53:39AM -0500, Michael G. Katzmann wrote: > On 2/22/21 8:18 AM, Johan Hovold wrote: > > I tried hardcoding buf[6-0] in pl2303_set_termios as > > a8 a6 01 80 00 02 07 and got a bitrate of ~200kb > > so, no these settings do not work in my case (or I missunderstood your > instructions 8-)) Thanks for testing (and that was with 0xa8 in byte 0, right?) So it seems we have three devices with bcdDevice 0x0300 encoding the divisors in slightly different ways and that are all still supported by the vendor's Windows driver. Unless Prolific are willing to shed some light on this, I guess someone needs to try to figure out how the Windows driver determines which encoding to use. Is your device supposedly also a PL2303 TA? Could you post the output of lsusb -v for completeness? Johan