[no subject]

[JONL at MIT-MC (Jon L White)]

From:     MILLER@MIT-AI
Date: Sun, 1 Sep 80 11:36:28 GMT
Original-Date: 01/09/80 07:36:28 EDT
Subject: Re:  SUPER-IMAGE Output
	There ought to be a way to OPEN a TTY file in "SUPER-IMAGE" mode, or a
    builtin "RAWTYO" function.  These would, on ITS, prefix any special
    characters with a control-P.  On 20X they would put the TTY in binary mode
    during TYO's.  The way things are, it is very difficult to write terminal
    hacking stuff in LISP except in a very operating-system-dependent way.  I
    have spent a lot of time changing my own code from sending control-P's to
    instead call appropriate JSYS's on 20X.  The amount of code you'd have to
    put in LISP to support this is probably less than a page of MIDAS.  LISP
    ought to provide that as a primitive, even if it only works on some systems
    initially.  Writing code which does (TYO control-P) (TYO escape) ... at the
    user level is pretty obscure!  Regards, Mark
I believe that the idea of the CURSORPOS function was to abstract out the
various "terminal hacking stuff", and refer to them as symbolic arguments
(or numeric positions) to CURSORPOS.  Indeed, the maclisp implementation 
of CURSORPOS does the appropriate "lock-out" so that control-p codes are
not separated from the preceeding control-P.  Shouldn't you do that too?
namely, just add to the code for CURSORPOS in the midas listing?  It
may be that you will want to add more commands to account for the TOPS-20
or TENEX terminal capabilities.   
    I've just edited the sources to separate out the ITS-relevant parts, 
and you will find in the file MC:LISP;*LISP >  a page which has a part 
"SUBTTL<tab>CURSPOPOS<space>FUNCTION"  and that should be changed whereever 
there are conditionals marked by either  "IT%" (meaning, "not ITS") or "IT$" 
(meaning, for ITS), or "IFN ITS," (also for ITS);  the only things relevant 
there are how to read the cursorposition from the terminal, and how to move 
it (the "H" and "V" commands from CURSORPOS).  Also, in the file MC:L;QIO >
there is a page with a part "SUBTTL<tab>CONTROL-P<space>CODES", and this will 
have to be scrutinized more carefully, since here it is that symbolic commands
are translated into real action.
   This new source will be the one which you (MILLER) will receive on
the tape which is being made up this week for mailing to you.  As you remember,
when the source is shipped out, it is "unified" into one long file.