🚀 go-pugleaf

In an earlier message, I said I had the following problem:
(1) I use DVIVGA and have no difficulty using the arrow keys and page up,
    page down, home, end keys with it.
(2) I use DEMACS and then exit DEMACS
(3) I use DVIVGA and the arrow keys, home,end,pageup,pagedown don't work any 
    more.

I have solved the problem in a certain sense. First I'll explain the solution
and then I'll explain why I am still not happy.

Originally, I had installed ANSI.SYS in my CONFIG.SYS file with the line:

DEVICE=C:\DOS\ANSI.SYS

With this, the problem was as above. After reading the DOS4.01 manual,
I changed the line to:


DEVICE=C:\DOS\ANSI.SYS/x


The /x option tells DOS that I have an extended keyboard and that the
arrows,home,end,pageup,pagedown on the numeric keypad are different from
the other keys of those names. When I use DVIVGA after running DEMACS,
I am unable to use the arrows, pageup,pagedown,home,end on the
numeric keypad, but I can use the other versions of these keys.

So my problem is solved, except I remember I used to be able to do it
in the numeric keypad even after using DEMACS. And the question still
bothers me: why is DEMACS exhibiting after effects?

One possibility is that DEMACS has some kind of Terminate and Stay REsident
feature, but I doubt that. So the other possibility that occurs to me
is:
(a) when DEMACS starts up, it somehow redefines the keyboard, using termcap
    information and stuff in some file in the directory TERM.
(b) when it exits, DEMACS does not clean up after itself and restore the
    original settings.

I plan to start looking at some of the various .el files that come with
DEMACS to hunt for clues. The file STARTUP.EL in the LISP directory and
the file IBMPC.EL in the TERM directory seem like good candidates. However,
I don't know whether the commands in these files have effects outside of
DEMACS. The other thing that seems logical to look for would be files
that tell DEMACS what to do before it exits. I haven't found these and
don't know if they exist.

It would also make sense to try to find all commands in the various .el
files that that affect the numeric keypad. After all, it seems that the
entire problem is that DEMACS stomps on the numeric keypad and leaves 
it stomped.

One other clue might have to do with error handlers, i.e. what happens
when DEMACS can't decide what kind of file it is dealing with. I usually
use DEMACS on TeX files and I don't have the .EL file for TeX. So I always
get an error message about being unable to find the .el file for tex.

I don't know if I will find the solution right away, but it seems that I
will perhaps emerge from this experience knowing something about elisp. :-)

Allan Adler
ara@altdorf.ai.mit.edu