echoing style - DOS,VMS vs. Unix (was: AT&T Joining OSF)

[Curtis Villamizar]

In article <12016 at steinmetz.ge.com> davidsen at crdos1.UUCP (bill davidsen) writes:
>	one of the few things I like about DOS and VMS is that the
>characters are echoed as they are read, not as they are typed. This
>prevents display of info designed to be read "no echo." Fortunately
>there seems to be no reason why this can't be done in a device driver,
>even if it's not (I would like to think it is and I haven't found it).

Actually you would want to implement this as an alternate line disipline in
most Unix versions.  I had done that in a past life (while employed by Perkin
Elmer) for IDRIS, a V6 look-alike, on a 68000 based computer, and for Sys III
on the same toy.  (PE still sells the system with IDRIS, bundled in turnkey
scientific instrument systems (which required real time enhancements - (which
was the real fun stuff))).  The line dicipline allowed "delayed echo" to be
turned off - a lot of people prefer that.

The real advantage of delaying echo is input gets put on the screen where
it belongs, not where the cursor happened to be when the character was typed.
This is a plus for "cooked" mode applications which use cursor movement.

The "new tty" line dicipline on my Sun which I presume either Berkley or Sun
did is an example of an alternate line dicipline.  When I go back to Sys V,
I am always annoyed when it backspaces over my prompt and does other stupid
things.  This kind of code gets put in the line dicipline once, and can be
used with any device driver (including pty's).

I think this would be done in a streams layer on Sys V.3 but I'm not sure.
Does anyone know if line diciplines are obsolete and replaced by streams stuff?

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