On Sat, 7 Oct 2017, Rob Jarratt via cctalk wrote: > I can get output on the alternative serial console, but no matter what I do > with the setenv console command, or installing/removing the video card, the > firmware console will not take input from the alternate serial console. > However if I boot Ultrix to single-user mode, I can type commands into the > serial console quite normally. This tells me that there is nothing wrong > with the cable or the emulator. > > > > Does anyone know why I cannot type input to the firmware console from the > alternative serial console?
Can you check the status of the flow control and modem lines? Under Linux this would be `statserial /dev/ttyS0' or suchlike (i.e. substitute `/dev/ttyS0' for the terminal device you're actually using to connect to your DECstation). Chances are the firmware does not drive the RTS and/or DTR lines, while Ultrix does, and your communication software wants to see either or both active before transmitting anything. You can try to set your terminal device to ignore these lines regardless of whether you actually have a way to probe for these signals available, e.g. again on Linux this would be `stty -F /dev/ttyS0 clocal -crtscts', or if your communication software is more sophisticated than, say, `cat', then it may offer you its own way to control these settings. Other *nix systems should have similar controls, especially `stty' is a pretty standard tool. I can't give you specific help with non-*nix OSes, however the general principles of serial communication outlined here still stand. Alternatively, there's a hardware solution possible, by rewiring the serial connection cable such that at each end RTS and DTR locally loop back to CTS and DSR respectively. HTH, Maciej
