[comp.sys.mac] Defence against a VT100 Maculator slur...

sqrkl@csvax.liv.ac.uk (06/30/88)

In article <46100170@uxe.cso.uiuc.edu>, leonardr@uxe.cso.uiuc.edu writes:

>I am new to this mac world.  I downloaded the VT100 emulator posted
>on this net a while ago and I tried it at home.  It seemed no problem
>until I ran emacs.  My screen was completely garbaged after I started
>the emacs.

I assume you are talking about my terminal emulator ("VT100 Maculator") -
you don't mention any names though...! I must confess to have never used
emacs (although I have played with a variant called 'Jove' which was pretty
awful). It all depends on what escape sequences emacs sends - try switching
the Control Chars option to 'Visible' (at least that's what I think I called
it) and noting down the sequences sent when you enter emacs. You could always
e-mail me a list of them and I will investigate...

> 	Sounds to me that the problem is not so much with the Mac itself, but with
> the terminal emulator in questions.  Since the Mac can handle input at 19.2Kb
> and above without any problem (I use the Telebit Trailblazer very frequently),
> it sounds like the emulator that you are using can not handle the character
> influx.

I strenuously deny this ! My emulator works fine at 9600 baud with XON/XOFF
active. It will support up to 57600 baud and has done so when talking to my
Amiga...

>  I use MicroPhone II for my VT100 emulation and find it flawless.

I've heard this one before ! Pull the other one - it's got bells on ! Everyone
says how wonderful [fill in your favourite VT100 emulator here] is, but
whenever I get to see and use them, they have some nifty gizmo features (28
varieties of uploading/downloading, fancy Tek graphics, macro facilities etc.),
but the emulation is ALWAYS (without exception) lousy...

> it with vi and Emacs and have had NO problems at 2400 baud.

Treble ugh ! vi, Emacs and 2400 baud - what a disgusting trio that makes...

A note to VT100 Maculator fans :
Version 1.32 is in the works and will (hopefully) be released as a freebie
soon. This version will fix all known bugs (although the 'delete-6-spaces-
before-the-cursor-on-a-Mac-II' bug still has me perplexed !) and will have
Newline mode added for UN*X masochists.

Sorry for the delay, but all my efforts going into the Acorn Archimedes version
at the moment - it's looking rather sensational if I say so myself...in fact,
it's looking so amazing (here's modesty for you), that I may well go commercial
with the Archimedes version (beats the socks off that ArcTerm rubbish).

Richard K. Lloyd,       ****** This is a VAX 11/780 running VAX/VMS V4.5 ******
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Merseyside, England,    * Internet  : SQRKL%csvax.liv.ac.uk@cunyvm.cuny.edu   *
Great Britain.          *******************************************************

"My opinions and those of the University of Liverpool are completely unrelated,
so I'M THE CULPRIT if you feel offended by the above message - I just can't
help moaning about Atari STs, PCs or clones, U**X, C, IBM mainframes, the list
is endless..."

flash@ee.qmc.ac.uk (Flash Sheridan) (07/01/88)

In article <3601@csvax.liv.ac.uk> sqrkl@csvax.liv.ac.uk writes:
>In article <46100170@uxe.cso.uiuc.edu>, leonardr@uxe.cso.uiuc.edu writes:
>
>>I am new to this mac world.  I downloaded the VT100 emulator posted
>>on this net a while ago and I tried it at home.  It seemed no problem
>>until I ran emacs.  My screen was completely garbaged after I started
>>the emacs.
>
>I assume you are talking about my terminal emulator ("VT100 Maculator") -
>you don't mention any names though...! I must confess to have never used
>emacs (although I have played with a variant called 'Jove' which was pretty
>awful). It all depends on what escape sequences emacs sends - try switching
>the Control Chars option to 'Visible' (at least that's what I think I called
>it) and noting down the sequences sent when you enter emacs. You could always
>e-mail me a list of them and I will investigate...

Dunno, sounds plausible to me.  Jove breaks uw's vt100 emulation, but not 
Red Ryder's or dumb virtues.  Recompiling without 'insert' set improves
things, I think, but lines still get left after they should be deleted.
This doesn't necessarily apply to yours, of course; I can't test it, as I
have a Mac II.

From: flash@ee.qmc.ac.uk (Flash Sheridan)
Reply-To: sheridan@nss.cs.ucl.ac.uk
or_perhaps_Reply_to: flash@cs.qmc.ac.uk

levin@bbn.com (Joel B Levin) (07/02/88)

In article <3601@csvax.liv.ac.uk> sqrkl@csvax.liv.ac.uk writes:
(In article <46100170@uxe.cso.uiuc.edu>, leonardr@uxe.cso.uiuc.edu writes:
(
(>I am new to this mac world.  I downloaded the VT100 emulator posted
(>on this net a while ago and I tried it at home.  It seemed no problem
(>until I ran emacs.  My screen was completely garbaged after I started
(>the emacs.
(
(I assume you are talking about my terminal emulator ("VT100 Maculator") -
(you don't mention any names though...! I must confess to have never used
(emacs (although I have played with a variant called 'Jove' which was pretty
(awful). It all depends on what escape sequences emacs sends - try switching
 . . .
(> it sounds like the emulator that you are using can not handle the character
(> influx.
(
(I strenuously deny this ! My emulator works fine at 9600 baud with XON/XOFF
(active. It will support up to 57600 baud and has done so when talking to my
(Amiga...

All the versions of EMACS I have used on host computer systems do not
like XOFF/XON; they actually use ^S and ^Q as command characters and
try to fix slow the output to the screen by padding with invisible
characters (which, needless to say, does not help the problem of a
slow character handler) or maybe in some cases by actually pausing to
let the screen catch up.  This kind of behavior can be really painful,
of course.  An emulator which is fast enough for EMACS really has to
be fast enough without flow control; and the combinations of the
various EMACS (Ultrix, Sun, TOPS-20) with the Mac VT100 emulator I use
work fine.

	/JBL


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mkhaw@teknowledge-vaxc.ARPA (Mike Khaw) (07/02/88)

>From article <3601@csvax.liv.ac.uk>, by sqrkl@csvax.liv.ac.uk:
> I strenuously deny this ! My emulator works fine at 9600 baud with XON/XOFF
> active. It will support up to 57600 baud and has done so when talking to my

How fast does it (Maculator) go WITHOUT xon/xoff?  Emacs uses ^S for
"incremental search", and ^Q for "quote" (to allow you to insert control
chars into your buffer).

Mike Khaw
-- 
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hardcopy: Teknowledge Inc, 1850 Embarcadero Rd, POB 10119, Palo Alto, CA 94303

denbeste@bgsuvax.UUCP (William C. DenBesten) (07/05/88)

Someone wrote:
> I am new to this mac world.  I downloaded the VT100 emulator posted
> on this net a while ago and I tried it at home.  It seemed no problem
> until I ran emacs.  My screen was completely garbaged after I started
> the emacs.

In article <26472@bbn.COM>, levin@bbn.com (Joel B Levin) writes:
> All the versions of EMACS I have used on host computer systems do not
> like XOFF/XON; they actually use ^S and ^Q as command characters and
> try to fix slow the output to the screen by padding with invisible
> characters (which, needless to say, does not help the problem of a
> slow character handler) or maybe in some cases by actually pausing to
> let the screen catch up.  This kind of behavior can be really painful,
> of course.  An emulator which is fast enough for EMACS really has to
> be fast enough without flow control; and the combinations of the
> various EMACS (Ultrix, Sun, TOPS-20) with the Mac VT100 emulator I use
> work fine.

The solution to this problem is to rebind keys so that emacs
effectively ignores xon/xoff, and move the commands that were on those
keys to a different key.  At my site, we have set up a site-wide
initialization file for emacs that does just that.  If you want to do
it for yourself, put the following in your .emacs file.  If you have
none, create a file, ~/.emacs and put the following in it:

8<------------------------------ Cut Here ------------------------------>8
;;;	$Source: /u1/third_party/gnuemacs.v17/lisp/term/RCS/xon.el,v $
;;;	$Author: rlk $
;;;	$Header: xon.el,v 1.1 86/01/29 14:51:49 rlk Exp $


(set-input-mode nil t)
(setq keyboard-translate-table
      "\000\^a\^b\^c\^d\^e\^f\^g\^h\^i\^j\^k\^l\^m\^n\^o\^p\^q\^r\^s\^t\^u\^v\^w\^x\^y\^z\033\^q\035\^s")
(setq losing-keyboard t)

(defun help-for-losing-terminal ()
  "Describe losing flow-controlled terminals."
  (let ((buffer (current-buffer)))
    (pop-to-buffer (get-buffer-create "*Help*"))
    (insert
"The terminal you are using reserves the C-s and C-q characters for a special
use, known as auto-Xon/Xoff flow control, and thus you cannot use these
characters for any purpose, and neither can Emacs.  Therefore, we have to
replace any key combinations (such as C-s and C-x C-q) with new key
combinations not using these characters.

We have chosen the characters C-~ (or C-^ on some terminals) and C-\\ 
(control-backslash) to directly replace these characters, to make the
conversion easier.  Very few commands are bound to keystrokes using these
two characters, thus this should not be too much of a problem.  If you
accidentally type C-s by mistake your terminal will freeze and you will have
to type C-q to unfreeze it.

For example, the command to search forward, which is bound to C-s, will now be
bound to C-~.  The command to insert the next character typed, C-q, is now
C-\\.  The command C-x C-q is now C-x C-\\.")
    (pop-to-buffer buffer)))

8<------------------------------ Cut Here ------------------------------>8

-- 
 William C. DenBesten
 denbeste@bgsu.edu