getch() and getche() in MSC 4.0

[Guy Harris]

>A related suggestion...  I have a program that makes '_' an alphabetic
>by changing _ctype[].  This was a bad idea since 1) the "array" has a
>different name on different systems, eg. BSD vs. AT&T,

Try "AT&T vs. AT&T"; V7 used "_ctype_", and a different AT&T release (S3
or S5) removed the "_".

Don't assume every place where BSD and S5 differ is the result of AT&T
and Berkeley deciding to do things differently; sometimes it was just
one or more parts of AT&T deciding to do things differently....

And yes, it was a bad idea (I think the S5 "m4" code does the same
thing); don't assume you know the way some system-defined function works
internally, because some day you may find a system on which it works
differently....  (Furthermore, some library routine your program calls
may have expected "isalpha('_')" to be false, in which case it was in
for a rude surprise.)