mf@ircam.UUCP (Michel Fingerhut) (11/30/87)
One of the terminals we have on a dz line (on a VAX 750 running 4.2bsd) uses an even parity bit (besides 7 bits of data). The dz board does not generate the parity bit on output (though checks it on input). I patched dz.c to add this bit (using the partab array in tty.c) on output to this line in either raw or cooked mode (emacs writes in raw mode...) I would like to distinguish such lines with a bit in the tty structure. I used the L001000 bit in the local mode word, with the advantage that it can be set through the f2 parameter in the /etc/gettytab entry for the terminal spec. Unfortunately, /etc/login zeroes the whole word (why on earth?) with ioctl(0, TIOCLSET, &zero) with the result that as soon as it prompts for login, garbage comes out on the screen. I would like a suggestion for a "safe" bit in the tty struct (or elsewhere, in a place "naturally" accessible to the driver), i.e., one that is unused in the true sense of the word, and that can be set using entries in gettytab (e.g. f2), or otherwise but with a minimum number of patches to kernel and programs. I'd appreciate replies by e-mail (...!uunet!ircam!mf). Michael Fingerhut PS: Why do we use this terminal, you ask? Well, anyone can get it for free in France, and it has a built-in modem (a.k.a. Minitel 1B).