Miscellaneous Notes

The feature msdos is included in the *features* list and can be used for conditional evaluation of DOS-specific code.

Since the DOS operating system uses the backslash character \ as the directory separator and the backslash character is also the Lisp escape character, a file name string that is specified within XLISP-STAT, for example as an argument to the load command, must be entered with two backslashes. For example, a file foo.lsp in the subdirectory bar of the current directory would be loaded using

(load "bar\\foo.lsp")

or by

(load "bar\\foo")

if the .lsp extension is dropped.

DOS imposes an 8-character limit on base file names. When asked to access a file with a longer base name, file system functions truncate the base name to 8 characters. Thus

(load "regression.lsp")

is equivalent to

(load "regressi.lsp")

If you have files that uses a longer name on other systems you can therefore truncate their names as long as they are unique in the first 8 characters.

There are several features that are either missing, not yet implemented, or only partially implemented:

• Clipping is not yet implemented in the graphics system. I have not yet figured out how to remove clip regions from a device context.
• A mouse is essentially required for the graphics windows and dialogs. A proper alternate keyboard interface is not yet available.
• Listener and graphics windows do not have a maximize button. The reason for this is that strange things seem to happen when the menu bar is modified while windows are maximized. You can maximize the MDI frame and then resize windows within the frame.
• WXLS has access to all the memory Windows makes available to it, but because of the segmented architecture of the 80X86 processor, no single item larger than 64K can be allocated. This limits the total number of elements in a Lisp array to 16K and the total size of a numerical array used in the linear algebra functions to about 8K elements. There is little guarantee that violations of these limits will be handled gracefully. This limitation does not exist in the Win32 version 32.
• The Win16 version has a system stack of only 20K. The Win32 version is limited to a system stack of about 70K when run under Win32s, but should have a much larger stack of 250K under Windows NT.