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From: bzs@bu-cs.BU.EDU (Barry Shein)
Newsgroups: comp.unix.questions,comp.unix.wizards
Subject: Re: Dealing with dial-up lines
Message-ID: <20001@bu-cs.BU.EDU>
Date: 19 Feb 88 01:15:48 GMT
References: <2995@bloom-beacon.MIT.EDU> <2594@codas.att.com>
Organization: Boston U. Comp. Sci.
Lines: 29
In-reply-to: mikel@codas.att.com's message of 18 Feb 88 05:00:22 GMT

Posting-Front-End: GNU Emacs 18.41.4 of Mon Mar 23 1987 on bucsd (berkeley-unix)



>	a. You've got very old hardware that doesn't understand
>	   hangups (ie: VAX dh boards, I beleive).

Actually the dh supported an astounding amount of modem control not to
mention other configurations (20mA and some sort of "teletype"
interface etc.)  Unfortunately DEC never supported it on the VAX,
mostly they were used on "real" systems on DEC10's and 20's (BSD Unix
supported dh's on Vaxen, you could plug dh's in and they worked much
better than supported options due to modem control and real on-board
DMA buffering tho you usually got flak from field circus if they
broke, "we can't fix those, we only took your money cause we needed
it".)

The mux's they *did* support on the Vax were pretty weak on modem
control (DZ's were acceptable but had no DMA at all, DMF's came later
with DMA but 6 out of the 8 ports lacking any modem control, anything
after that wouldn't qualify as "older".) I don't know that anyone ever
ran DL's on a Vax, only the "E" had modem control (at the cost of
using an entire board for one serial line) as I remember, but they
were PDP-11 interfaces (I guess they could be run on a Vax Unibus,
maybe not enough address bits in the control registers to make them
practical.)

Anyhow, the answer to the question was the flag bits in his config
file (we spoke off-line), tho the other suggestions are always worth
checking.

	-Barry Shein, Boston University