Notes about MS-DOS executables and compilers:

 - Borland start-up code is reported to switch the screen mode auto-
   matically if it's not 80 columns (or possibly 40) and either 25, 43 
   or 50 lines.  In particular, extended modes such as 100x40 are not
   retained.

 - Borland start-up code also uses interrupt 1Ah, causing incorrect
   behavior (including lock-ups) on some Japanese MS-DOS machines such
   as the Fujitsu FMR series, which lack this interrupt.

 - Some(?) Borland compilers are apparently incapable of putting static
   data into far memory; this means all of UnZip's strings are in near
   memory, and there is not enough room to enable ZipInfo in the small
   memory model.  The medium memory model is the default for now, but
   it may be necessary in some cases to use the large model.

 - Older Borland compilers do not understand source files with Unix
   line-endings (LF rather than CR/LF).  Use "flip" or a similar utility
   to convert the line endings before compiling.

 - The Borland 5.00 compiler is simply too buggy to use on WizUnZip, both
   16-bit and 32-bit versions, and we recommend avoiding it for now even
   on the commmand-line version of UnZip.

 - Microsoft C 5.1 large-model code is more than an order of magnitude
   slower than the identical code compiled with MSC 6 or 7 (a factor of
   15 in our tests, actually).  This may be due to a lousy optimizer or
   lousy libraries; regardless, since UnZip is hovering at the doorstep
   of the large memory model, we recommend upgrading to a later version
   of the compiler.

For these reasons, Info-ZIP's distributed versions of the 16-bit MS-DOS 
executables are compiled with MSC 6 or 7.

 - The default wildcard ("globbing") behavior of djgpp/go32 is disabled
   by default in UnZip, but this can be overridden if the GO32 environment
   variable is set to "glob".  This will cause UnZip to fail with various
   odd errors about "filename not matched" and the like; to avoid this, set
   the GO32 variable to "noglob" or unset it altogether.  (The documented
   method of avoiding this by quoting wildcards with single quotes was 
   buggy in djgpp 1.11 but is reported fixed in 1.12; not tested.)

 - djgpp's handling of timezones, necessary for the correct conversion of
   MS-DOS filetimes to those used in the Unix-like C library, is completely
   broken in djgpp 1.12 and probably earlier versions as well.  It is fixed
   (or very close to it) in the 1.12m4 patch release and reportedly in the
   2.x series, so be sure to use one of those when compiling.  Otherwise
   UnZip's -f and -u (freshen/update) functions will not work correctly.

 - djgpp/go32 executables, when run in a DOS box under OS/2 *and* extracting
   to an HPFS disk *and* overwriting existing files (intentionally, that is),
   do not set the files' timestamps correctly.  Instead, the timestamps re-
   main set to whatever the original files' stamps were.  This is a pretty
   obscure bug, but it does *not* occur in the 16-bit version so it seems
   to be go32's fault somehow.

 - According to notes found in another package, there was a known conflict
   between djgpp 1.x's go32 extender and QEMM's DPMI; this was apparently
   fixed in QEMM 7.04/QDPMI 1.05, but if you still have an older version
   (1.03 or 1.01), add "set GO32=nodpmi" to your autoexec.bat to avoid the
   conflict.)

 - [For Zip only, the djgpp/go32 extender goes nuts with the copying and/or
   deletion of some sort of a temporary file (swap file?) after compression
   is finished; this can take 30 seconds or more and really hurts perfor-
   mance.  It doesn't affect UnZip, apparently.]

 - emx+gcc's DOS extender does not understand DPMI, and while there is an
   alternative extender called RSX available (found in dpmigcc4.zip as of
   August 1994), its setup is somewhat kludgy when the local memory manager
   supports both DPMI and VCPI (or something else).  It's also not yet as
   widely known or available as djgpp.

For these reasons Info-ZIP's distributed 32-bit MS-DOS executables will 
probably be compiled with Watcom C 10.x and use the PMODE/W extender.  If
a problem occurs with unzip386.exe, check first if it also occurs with
unzip.exe before reporting it.

GRR 960427