If you type in the tcl_library and tk_library environment variables and get an out of space error, you can increase the amount of
memory allocated to the DOS environment through the COMMAND.COM command line options. For example, add the following
line to your CONFIG.SYS file:
shell=c:command.com /e:1024 /p
This sets the environment space to 1K. Note that (on my system, at least) the /c autoexec command is needed to make DOS run
the autoexec.bat file during booting.