[net.micro] termcaps *!#@$#!!

prindle@nadc (01/19/85)

Does anyone know that there is a lengthy dissertation in the UNIX
manual (TERMCAP (5)) which tells you exactly how to define a termcap
entry for any terminal as long as you know what it can do, and what it
can't!  For the umpteenth time, there is no such thing as a termcap
entry for a *computer*!  There can only be a termcap entry for a
computer/terminal-emulation-program combination, and it is 99%
dependent on the terminal-emulation-program.  If you are using a dumb
terminal program, then you might as well settle for a terminal type of
"du" and use "vi" in the "open" mode; no amount of diddling with a
termcap entry will make your terminal program any smarter.  Also, even
if you define a perfect termcap entry for your computer/program combo,
many programs are hopelessly frustrated (eg. rogue) or lose
information (eg. emacs) when the screen width is less than 80 columns;
vi is the most adaptable.

William Chops Westfield <BillW@SU-SCORE> (01/19/85)

Well, i almost agree with you.  Some PCs have a built in terminal
emulator, and so it is ok to ask for a termcap for a DEC rainbow, or
an H89, or an HP150.  Frequently the problem with writing you own
termcap is that you dont know what the PC in question can do.  there
are plenty of programs that say things like "emulates a vt100", while
neglecting to tell you that scolling regions aren't implemented.  Telling
someone to write their own termcap is in some cases akin to telling someone
to write a terminal emulator that emulates some terminal already in termcap!

For people that request termcaps, you should be aware that in most cases,
the type of software that you are running is just as important as the
hardware, so requests should be "does anyone have a termcap for the Vic20
running version 4 of VicTalk from unfriendly software inc?".  Also, there
are a number of "standard" terminals that are "likely" to be emulated
if anything at all is emulated.  In decreasing order of capability,
these are: VT100 (ANSI), VT52, ADM3A - you can try out these termcaps
(or variations thereof reflecting real length and width of the screen),
before requesting some other termcap...

BillW

werner@ut-ngp.UUCP (Werner Uhrig) (01/19/85)

[chomp - crack .....  my kingdom for a dentist]

ever since first encountering "termcaps", and every time I have to deal with
one again, I've done  "wishful thinking"  for a program, which accepts a
termcap as input, and gives you an annotated listing of what the attributes
described in the termcap are "in English".  A little interactive program
allowing you to set / modify  parameters from a menu-driven interface also
seemed reasonable to long for.  Alas, I never followed up and asked around
or went off into my corner to write some code ...  anyone care to make my
day ???  (and, undoubtedly, of many, many  millions and billions .... )

[is that the sun rising over the garden fence ???? just another day of blue
  sky and temperatures in the 70s - sigh, and I'll sleep right through it .. ]

rsellens@watdcsu.UUCP (Rick Sellens - Mech. Eng.) (01/23/85)

Re: no termcaps for a *computer*

In general you can't define a termcap for a computer, but there are
some machines which have screen handling capabilities built into
the console device driver. In particular ANSI.SYS on the IBM PC is
supposed to make the pc console react to ANSI terminal escapes.
Apparently it is a little buggy, but with a transparent (keyboard to
RS232_out, RS232_in to console) terminal program you can get a
reasonable facsimile of a full screen terminal, provided you are
using an *appropriate* termcap entry. Because of this there has been
a fair bit of traffic in "termcaps for the IBM PC" which cover the
appropriate subset of the ANSI stuff.


Rick Sellens
UUCP:  watmath!watdcsu!rsellens
CSNET: rsellens%watdcsu@waterloo.csnet
ARPA:  rsellens%watdcsu%waterloo.csnet@csnet-relay.arpa

gordon@sneaky.UUCP (01/27/85)

> /* Written  1:23 pm  Jan 23, 1985 by watdcsu!rsellens in sneaky:net.micro */
> 
> Re: no termcaps for a *computer*
> 
> In general you can't define a termcap for a computer, but there are
> some machines which have screen handling capabilities built into
> the console device driver. In particular ANSI.SYS on the IBM PC is
> supposed to make the pc console react to ANSI terminal escapes.
> ...
> 
> Rick Sellens
> /* End of text from sneaky:net.micro */

That's funny, I wasn't aware that the console device driver was implemented
in hardware that couldn't be gotten around by any means.  There are plenty
of different operating systems that run on the IBM PC, and Xenix, among others,
never heard of ANSI.SYS, even if it has similar capability.  It also
isn't unheard of for terminal emulator programs to go direct to the hardware
on both screen and communications devices to speed things up, get around
operating system bugs, or just do things differently.

					Gordon Burditt
					...!ihnp4!sys1!sneaky!gordon
					...!convex!ctvax!trsvax!sneaky!gordon