Frequently Asked Questions about TkWin

1.  What is it?

TkWin is a port of Ousterhout's Tcl/Tk package to Microsoft Windows 3.1.
It was developed by the Mathematical Sciences Computing Facility at
the University of Kentucky; the first release appeared July 4, 1994.

There is an update available dated July 20, 1994.

2.  Where do you get it?

TkWin can be obtained via anonymous ftp from ftp.ms.uky.edu in /pub/tk-win.
The current version of the sources is tkwin.zip; the binaries are
in tkwinbin.zip.

Mirrors are at
	ftp.ibp.fr:/pub/tcl/tk-win
	mrrl.lut.ac.uk:/tcl-tk/tk-win

3. How do you execute Tcl/Tk commands from a file?

Because there is no shell and so no "#!" convention, Tcl scripts cannot
be directly executed.  You need to specify the executable in the command
line.  For example:
	wish -f /myscripts/myfile.tcl -t -c
where you can drop off the -t if your script doesn't make tcp connections
and can drop -c if you don't care to have a console window (the console
window is mostly for debugging).

The above command line can be typed into the Program Manager's File/Run
menu option or you can make a program item with it using File/New.

If you already have a wish running with a console window, you can also
simply type in the command
	source /myscripts/myfile.tcl

You can also use the File Manager.  To do this, first use File Manager
File/Run to run regedit.  Choose Edit/Add Filetype and fill in the entry.
For example, you could use Identifier: tclfile, File Type: Tcl/Tk Script,
Command: wish -t -f %1, and click on Uses DDE to de-select it; then hit OK
to register the new type, and exit from regedit.  From the File
manager, select File/Associate.  Fill in TCL as the extension and select
the Tcl/Tk Script Filetype to associate it with; click OK.  Now you should
be able to click on .tcl files in the File Manager and have them run
wish -t -f on them.

4.  Are there size limitations in TkWin?

There are at least two sources of size limitations.  

First, integers are 16 bit integers.  Typically, this is not a problem
but because the code came from a 32 and 64 bit world, it would have been
easy to have overlooked some places where 32 bits are needed.  In fact,
there are some places where I know that 32 bits would have been preferable,
but decided to stay with plain 16 bit ints because of the effect on the
code.

Second, TCL.DLL is a large model library with most things occurring in the
local heap.  This means that data structures in general and especially
strings are certainly limited to 64K.  In practice, I have found that
things tend to break down when objects get larger than about half that
size (though I do not know where this occurs).  There are similar limitations
on file i/o, which is serious because Tcl/Tk tends to want to read in
files in a single read.  In particular, you probably don't want to
source large files; break them up first.

5. What limitations are there on the Windows screen?

TkWin was developed on a 486 machine with 16 MB memory and a video controller
with 1 MB.  It has been tried on 386 machines with half the memory and
video controllers with only 256K; it did work, but...  One recommends:

First, that you set your screen resolution to 1024 x 768 (or finer)
if at all possible.  This is the resolution where almost all testing has
occurred; it also is close to the typical resolution of low end Unix 
workstations, where many Tk applications were developed.

Second, try to maximize the color depth.  In general, 16 bit works fine;
8 bits is tolerable, and 4 bits looks odd.  This is because the colors
are being approximated by what happens to already be in the palette,
rather than by generating the exact new colors.  Quite often on 8 bit
and 4 bit screens colors will appear as stippled patterns; this is being
done by the display driver, and not the tcl code, and so is machine
dependent.  

6.  Known problems as of July 20, 1994

a.  The console window doesn't display output of stdout and stderr.  

b.  There are problems under Windows for Workgroups.  Amongst other things,
apparently buttons do not work properly.  At the moment I don't have a copy
of WFW to work with...