Re: SUPDUP protocol


Rich Brennan (linus!alliant!brennan@husc6.harvard.edu)
2 Oct 87 13:40:14 GMT


In article <12338315541.10.BILLW@MATHOM.CISCO.COM> BILLW@MATHOM.CISCO.COM (William Westfield) writes:
>Although the SUPDUP [...] it does not provide for any
>local echoing capability at all, nor does it provide for local "break
>characters" [...]
>TOPS20 has the concept of a break character bitmap, but not for an
>echoing bitmap, [...]
>DEC's CTERM protocol provides the means of transmitting such info over
>a network connection [...]
>Unix, one of the worlds most popular operating systems, doesn't have
>either concept. The Annex boxes implement some local editing
>functionality, but this requires both a custom version of the editor,
>and custom software on the Annex, and is not a published standard.
>(nor does it help outside of the editor...)
>
>Bill Westfield
>cisco Systems

The local editing mentioned above is a special mode the Annex may enter
in either telnet, rlogin, or local mode. In fact, it does require a custom
version of an editor (gnu-emacs, currently). However, in its "native mode",
(Annex to Encore's Multimax), local editing, character batching, etc. are
all performed at the Annex. The initial developers of the Annex, Jonathan
Taylor (now of SUN Microsystems) and Rob Drelles (now of Stratus) designed
a "distributed tty driver" for the Annex and Encore's Unix OSes (both 4.2
and V); the bulk of the Unix tty driver(s) (both 4.2 and V), runs in the
Annex. In cooked mode, nary a character is returned to the host until a
"normal Unix forwarding character" is typed, i.e. something that would
cause characters to be moved from the raw to canonical queue. IOCTLs for
modem handling, lines speed changing, etc. are all processed. Of course in
raw/cbreak mode, there is little that may be done, though some character
batching (under control of a forwarding timer) may still be performed.

Rrrrrrrich.



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