Monster Media 1994 #1/monster.zip/monster/UTIL_ARC/UNZIP51X.ZIP/README.DOS

Text File | 1994-02-12 | 4KB | 78 lines

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.

 - 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, or take a look at the
   Borland.fix file in the UnZip source distribution.

 - 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 does not really fit into
   the small model anymore, 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.

 - djgpp/go32 1.11m2 apparently does not provide a way to disable its
   built-in wildcard expansion ("globbing") at compile time (or, if it
   does, we didn't find it).  In addition its handling of single quotes
   is incorrect.  SEE BELOW FOR A WORK-AROUND.

Info-ZIP's distributed 32-bit MS-DOS executables are compiled with djgpp
1.11.m2.  These are stand-alone programs; the "go32" DOS extender is in-
cluded inside the executables.  They generally run up to twice as fast
as the 16-bit versions, but they only work on 386's and above.  In some
cases they're actually slower.  If this is the case for you, first try
running under plain DOS, after removing any memory manager in your
config.sys and rebooting, to check if the slowdown is due to your memory
manager.  The problem may also be due to the time spent by the djgpp
runtime creating and deleting a swap file.  If you use SMARTDRV or another
disk cache, make sure that writes are also cached.

If you already have djgpp 1.11 or later, you can remove go32.exe from
unzip386.exe to get a smaller executable:

    exe2coff unzip386.exe
    coff2exe unzip386
    del unzip386

As noted above, go32/djgpp has its own wildcard-expansion routines, and
these are not compatible with UnZip.  The documented method of avoiding
this by quoting wildcards with single quotes is buggy:  trying to unzip
'..\*.zip' will result in the first file being unzipped, but none of the
others; trying to unzip ..\..\'*.zip' will result in go32 passing the
quoted string, with quotes intact, to UnZip (which can't find any files
with single quotes in their names, since they don't exist).  The only
method which does work is to set the GO32 environment variable to "noglob"
as follows (add to autoexec.bat, for example, or invoke unzip386 in a
batch file which has this setting):

    set GO32=noglob

With this setting quotes are unnecessary; unzip386.exe behaves just like
unzip.exe.

You may also need to set the TZ environment variable to get correct time-
stamps on extracted files when using unzip386.exe.  Adding the line

    set TZ=MET0

to autoexec.bat works for our French contingent; a Californian user might
need "set TZ=PST8PDT" instead.  The 16-bit version always uses local time.

For other problems related to DJGPP, read the documentation provided
in oak.oakland.edu:/pub/msdos/djgpp/djdev111.zip.  If a problem occurs
with unzip386.exe, check first if it also occurs with unzip.exe before
reporting it.