spiffy terminals

[Wilson Heydt]

In article <9357 at smoke.BRL.MIL>, gwyn at smoke.BRL.MIL (Doug Gwyn ) writes:
> In article <408 at ispi.UUCP> jbayer at ispi.UUCP (Jonathan Bayer) writes:
> >	The difference in cost is between $ 1000 and $ 1500.  When you
> >multiply this by the number of terminals in an office, the cost starts
> >to become prohibitive.
> 
> This line of argumentation has been refuted already, but let's try
> again:  Why not supply your office workers with packing crates or
> even cardboard boxes instead of real office furniture?  Just think
> of the savings!

The argument has only been refuted under restrcited conditions--not in
the general case.  There seems to have been an assumption made throughout
this discussion, to wit--the terminal (whether smart or dumb) is connected
directly to the host with a fairly high-speed link.  This is not always the
case--indeed it is frequently *not* the case.  Consider--with a dumb terminal,
if you want a screen-full of stuff you send the request to the host which
processes the request and shoots back about 2k bytes of data.  Ah!  Let's
use a smart terminal so we have very little host processing, then all the
host has to do is supply the raw data and let the *terminal* do the processing!
This can work great at 9.6 kbps or faster.  It's wonderful at 10 Mbps.
Think about the application I work with--a typical user wants that screen
of data.  The source data is in about 20, 800-byte records with a side
lookup to a 250-byte record for each one.  (I never said it was running under
unix.)   Now you've got to transmit up to 21,000 bytes of data so the
terminal can display 2k of them.  This is a disaster at 1200 or even 2400
bps over dial-up lines.   It's not too good at 9.6 kbps, either.  For
the price of a $2000 (or $3000, if you add the 'nice' features) terminal,
you are not going to get a $500 terminal and *2* 9.6 modems and claim to
be saving tons of money.  Any real speed improvement will require a jump
to a 56 kbps line and modems at that speed don't run over dial-up lines--
nor do they come cheap.  Net result--the real world doesn't do all it's
computing in the lab or in close proximity to fast connections.

   --Hal

=========================================================================
  Hal Heydt                             |    "Hafnium plus Holmium is
  Analyst, Pacific*Bell                 |     one-point-five, I think."
  415-645-7708                          |       --Dr. Jane Robinson
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