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From: jmunkki@kampi.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac
Subject: Re: Looking for good 160-column VT100 emulator
Keywords: 160-columns VT100 emulation
Message-ID: <21771@santra.UUCP>
Date: 1 May 89 11:07:05 GMT
References: <813@m3.mfci.UUCP> <11425@well.UUCP> <21712@santra.UUCP> <11468@well.UUCP>
Sender: news@santra.UUCP
Reply-To: jmunkki@kampi.hut.fi (Juri Munkki)
Organization: Helsinki University of Technology, Finland
Lines: 54

In article <11468@well.UUCP> svc@well.UUCP (Leonard Rosenthol) writes:
>	I will agree with you that there is no such thing as a perfect VT100
>emulator, both w/regard to emulating the STANDARD VT100 and to extensions to
>the STANDARD.  However it seems to me that extensions should be made with 
>care and with some standardization.  For example, the most common extension to
>the VT100 on the Macintosh is the presence of the scrollback buffer.  Also
>the ability to select text, and use the editMenu command on it.  

Right. Without these extensions a terminal emulator is not worth using.

>	Extending the VT100 with things such as >24 lines and >132 columns (or
>other wierd combinations) is, I guess, a nice thing to do, but what I don't
>see is how you can do that within the confines of the DEC VT100/ANSI specs.
>For example, when you do when the host issues the ESC[?3h or 3l to put it
>into 80 or 132 mode?  Is that what you do?  Is that what you SHOULD DO??

I took a look at what VersaTerm does when the window is resized to something
larger than 24 rows. A reset or ESC[r will default to the large screen size.
VMS & Unix first send an ESC[1;24r thus leaving a few lines below the
scrolling window. In unix I then type 'stty rows 36 ; reset', which changes
the screen size. After that, every program I've tried works just fine. The
reason is probably that window systems on unix have offered these nonstandard
sizes for ages. The same thing can be done with the screen width. The only
problem is that there is no escape code to do that. Currently my program
quickly changes back to 80 or 132 columns when it receives the escape. You
have to be careful that the program doesn't see one of these commands.

>	I am still trying to figure out how you would convince the HOST to
>give you two EMACS windows side by side...Anyway, I am not staying that having
>>132 columns is not a reasonable request, I am simply saying that this is the
>type of feature that needs to be WELL THOUGHT OUT before being implemented 
>otherwise my 160 column emulator may/will not work like yours and users will
>complain as they thought VT100 was a standard!??!?

The distributed version comes with a 80x24 or 132x24, but you can change the
default size with a ResEdit template (there will be a special defaults editor).
I think I'll allow the user to specify how many columns the 80 and 132 column
modes have. This way anybody who wants to use these features (like 160 columns
instead of 132) can do it. Most of the parameters than can be changes with
ResEdit (or the defaults editor) can result in strange behaviour in one or
the other way. One of the things you can do is change the font used on the
screen or for printing. I'm currently using Courier-10 instead of the default
font and it works fine, although you can't use the VT100 graphics character
set. I've also tried nonproportional fonts and they work well for reading
news & other stuff that doesn't require editing. I might restrict the defaults
editor to nonproportional fonts. You could still use Palatino for printing...

I think it is important to let the users decide what they can use. (Even
if they happen to be wrong.)

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|     Juri Munkki jmunkki@hut.fi  jmunkki@fingate.bitnet        I Want   Ne   |
|     Helsinki University of Technology Computing Centre        My Own   XT   |
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