ford@crash.CTS.COM (Michael Ditto) (10/04/87)
Further testing with a small C program to do the TCSBRK on ph0 revealed that doing the TCSBRK on /dev/ph0 DOES cause tty000 to become wedged. There was no response to keys typed on tty000, including BREAK. Output to tty000 (initiated by "echo foofoofoofoo > /dev/tty000" on the console) buffered up for a few hundred characters or so, but then would block. Stty could read the termio settings of tty000 (via "stty < /dev/tty000") but attempts to change them (via "stty -ixon < /dev/tty000") would hang indefinately. What finally made tty000 come back to life was "stty -ixon -ixoff < /dev/ph0". After that, tty000 worked fine. I send a TCSBRK to ph0 again, this time from the console, and again, tty000 froze. Again, "stty -ixon < /dev/ph0" made tty000 come back. Note that ph0 was ALREADY in -ixon mode, so it was simply a TCSETA to ph0 with no changes that made tty000 comp back. I did notice that when it came back, pending output did come out, but the keys I had typed on tty000 while it was frozen never showed up. Note that I ran these tests with kernel 3.51.1, (the 'tty000 break' fix) although these problems did happen with the normal 3.51 kernel. As I narrow down the problem further, hopefully it will reach a point where I have enough information to make a call to the "hotline" worthwhile. Send me any other details you discover... -- Michael "Ford" Ditto -=] Ford [=- P.O. Box 1721 ford@crash.CTS.COM Bonita, CA 92002 ford%oz@prep.mit.ai.edu