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From: chris@umcp-cs
Newsgroups: net.emacs
Subject: Re: terminal driver innards
Message-ID: <8101@umcp-cs.UUCP>
Date: Sat, 11-Aug-84 22:45:53 EDT
Article-I.D.: umcp-cs.8101
Posted: Sat Aug 11 22:45:53 1984
Date-Received: Tue, 14-Aug-84 00:59:55 EDT
References: <12243@sri-arpa.UUCP>
Organization: U of Maryland, Computer Science Dept., College Park, MD
Lines: 23

The fancy BaudFactor calculation was just one that happened to work
well for C100s.  In fact it does not work well for other terminals
as it produces a negative result for 19200 baud!  BaudFactor should
really be set to BaudRate/10000.0.

As far as the fancy IL and DL parameters go, ignore the comments in
Trm.h; they are at best misleading.  ILmf is the *padding* requirement
of a terminal and ILov is the overhead for doing an N line insert.  Of
course, that may not be a constant.  You just have to put in a ``best
guess''.

I have a document I wrote on writing terminal drivers for Emacs that I
could e-mail.  It's in TeX so you can't print nice copies with n/troff,
but you can still read it.  There's a catch, however:  it describes the
display.c code that I am using, and as far as I know there are three
or four people that have that code.  It's a rewrite of the #264 code,
with only the basic structure kept the same.  In particular, the cost
factors are represented differently, so I'm not sure it would be much
use in that respect.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci (301) 454-7690
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