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From: jnc@mercury.lcs.mit.edu (Noel Chiappa)
Subject: [TUHS] What's with the DZ-11?
Date: Thu, 27 Nov 2014 09:55:09 -0500 (EST)	[thread overview]
Message-ID: <20141127145509.5C8F418C0C7@mercury.lcs.mit.edu> (raw)

    > From: Clem Cole <clemc at ccc.com>

    > two issues. first DEC subsetted the modem control lines so running
    > modems - particularly when you wanted hardware flow control like the
    > trailblazers - did not work.

?? We ran dialup modems on our DZ11s (1200 bps Vadics, IIRC) with no problems,
so you must be speaking only some sort of high-speed application where you
needed the hardware flow control, or something, when you say "running modems
... did not work".

Although, well, since the board didn't produce an interrupt when a modem
status line (e.g. 'carrier detect') changed state, we did have to do a kludge
where we polled the device to catch such modem control line changes. Maybe
that's what you were thinking of?

    > To Dave the DZ was great because it was two boards to do what he
    > thought was the same thing as a DH

To prevent giving an incorrect impression to those who 'were not there', each
single DZ hex board supported 8 lines (fully independent of any other cards);
the full DH replacement did need two boards, though.

	Noel



             reply	other threads:[~2014-11-27 14:55 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-27 14:55 Noel Chiappa [this message]
2014-11-27 15:47 ` Ronald Natalie
2014-11-27 15:50 ` Ronald Natalie
2014-11-27 19:57 ` Dave Horsfall
2014-11-28 13:04   ` Ronald Natalie
  -- strict thread matches above, loose matches on Subject: below --
2014-12-01 12:32 Noel Chiappa
2014-12-01 15:46 ` Warner Losh
2014-12-01 16:41   ` Clem Cole
2014-11-27 16:03 Noel Chiappa
2014-11-26 21:41 Noel Chiappa
2014-11-26 20:48 Dave Horsfall
2014-11-26 21:39 ` Ronald Natalie
2014-11-26 22:08 ` Clem Cole
2014-11-27 19:45 ` Dave Horsfall
2014-11-27 20:55   ` Larry McVoy
2014-11-30  6:03   ` Warren Toomey
2014-11-30  6:43     ` Dave Horsfall
2014-11-30  7:03       ` Warren Toomey
2014-12-01  5:03         ` Dave Horsfall

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