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From: wilkes@mips.COM (John Wilkes)
Newsgroups: comp.arch
Subject: Re: DECSYSTEM 20
Message-ID: <24170@tau.mips.COM>
Date: 28 Jul 89 00:26:07 GMT
References: <11475@xenna.Encore.COM>
Reply-To: wilkes@mips.COM (John Wilkes)
Distribution: na
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 24

In article <11475@xenna.Encore.COM> cook@encore.com writes:
>I can't answer about the DL10.  On the 10 side the interface was called
>a DTE20 (DECsystem To Eleven).  The 11 didn't really have a great deal
>to do while timesharing was going on.  It handled unit record peripherals
  deleted...
>	- Dale (N1US)	Encore Computer Corporation, Marlborough, Mass.

It's been a few years, but i believe that the 11 also handled the serial
lines that connected terminals to the system.  Seems to me that it
interrupted the '20 for every character, passing them as tty,,char 16-bit
words.  If you used a loooong cable to the terminal, and it was not
actually connected, it would "ring."  The '20 would see some stray
character, and would spit out "Please log in" which would trigger more
ringing, which would cause the '20 to say "Please log in" etc.  This could
cause the load average to get quite high.

Ah, those were the days...  [DECsystem 20 continued]

(Pardon the non-arch posting; is it time for comp.sys.reminisce?)

-- 
-wilkes

wilkes@mips.com   -OR-   {ames, decwrl, pyramid}!mips!wilkes