🚀 go-pugleaf

In article <PSHUANG.92Oct25154538@freeside.ai.mit.edu> pshuang@zurich.ai.mit.edu (Ping Huang) writes:
>There was a three-part series of articles in recent issues of PC
>Magazine (I believe the issues which came out late August and September)
>which covered how to use the clipboard to communicate between DOS and
>Windows programs (the API to do so is documented by Microsoft). The
>articles explain how by using this ability to pass data back and forth,
>you could write a special Windows-side program which could make any
>Windows function call on behalf of a DOS program, communicating via the
>clipboard. 

I haven't seen the article, but the whole idea makes me cringe.  Certainly
it could be done. (There has been a DOS interface to the Windows clipboard
since Windows 2.x or before, offhand the only app that I know uses it
Word for DOS.)  This is a terrible misuse/abuse of the clipboard.  It would
basically disable all normal use of the clipboard between Windows apps.  
Somes like a marvelous way to alienate users to me.

>It also has some interesting things to say about the
>underused ability of Windows to dynamically link new functions at
>runtime.

Hmm... I didn't know this was underused, certainly it is a good thing.
GetProcAddress is your friend. :-)

>It is also possible (albeit relatively messy) to use an
>assortment of VDMA and DPMI function calls to implement shared memory
>between a Windows program and a DOS program.

This will work although you will typically end up doing polling on one
or both ends which is generally not to be desired.
(There is a minimal example of doing this in the TDOSMEM sample in the
3.1 SDK)

>[I wish Microsoft had published source code for the WXSERVER program
>which comes with the C++/7.0 product, which allows you to start up
>Windows programs from the DOS command line (e.g. "WX NOTEPAD" would
>bring up a copy of Notepad). It is not clear what method WXSERVER uses
>to do this. If anybody knows if Microsoft documents anything about
>WXSERVER or other IPC methods between Windows and DOS, I'd like to hear
>about it. Couldn't find anything on the recent Developer's CD-ROM.]

WXServer uses a virtual device driver to provide the IPC channel, in
particular vmb.386 is where the magic happens.  Although MS doesn't document
the interface that vmb.386 provides we do have a set of sample source that
demonstrates doing the same thing.  Have a look at VPOSTD on either CIS
or the MSDN CD-ROM.

-Blake
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