Instructions for Downloading Macintosh Files to DOS Computers

Larry Burns



This document explains what steps are necessary when you want to
obtain Macintosh files from an on-line service, such as Exec-PC, using a
DOS computer to download them.

There are three basic steps to follow:

        1.  Download the file to the DOS computer.
        2.  Transfer the file to the Macintosh.
        3.  Run BinHex5 to restore the file.


        
Downloading to a DOS Computer
-----------------------------
Any file transfer protocol can be used.  There is nothing special you have
to do other than download the file just like you would a DOS file.



Transfering the File to a Macintosh
-----------------------------------
You need a floppy drive on the Macintosh that will read DOS diskettes.
Examples are:

        - FDHD floppy drive by Apple (reads/writes Mac 1.44 Mb 3.5" disks).
        - Apple PC 5.25" Drive and adapter (reads/writes DOS 360 Kb 5.25" 
          disks).
        - DaynaFILE by Dayna Communications (comes in all DOS sizes & 
          formats).
        - Rapport adapter by Kennect Technologies (allows Mac 800 Kb 3.5"
          drives to read/write DOS 720 Kb 3.5" diskettes).

You also need a Mac program which can read DOS disks.  Examples are:

        - Apple File Exchange (comes free with the Mac operating system).
        - DOS Mounter by Dayna Communications.
        - AccessPC by Insignia Solutions.

For instructions on how to use these programs, please follow their
documentation.  If you use Apple File Exchange, remember to insert the
DOS disk AFTER you start up the program.



Running BinHex5
---------------
Does the following obscure situation sound familiar...

        The file "xxxxxx xxxxx" could not be opened/printed (the
        application is busy or missing).

Running BinHex5 will make it more lucid.  Obtaining BinHex5, however
may prove to be quite challenging!  Since you need this program to 
restore any files you download through the DOS pc, you will have to get a 
"pure" copy from some source other than yourself.  Mac user groups or 
fellow on-line subscribers may be able to help.

If you are restoring a file, such as a word processing document or 
application, containing binary type characters turn off the "TEXT filter"
option under "File".

Select "Download -> Application" under "File".

Select the file you want to restore.  Type in a new name for the restored
version of the file.

That is it!



Why Is All of This Necessary?
--------------------
Basically, you are putting the "single" file you downloaded back into its
original two files.  Every Macintosh file actually consists of two separate
files - a Resource Fork and a Data Fork.  These two files are stored separately
on disk (physical files) but presented to a user as one (logical file).

Because DOS computers have only one physical file for each logical file, Mac
users would have to upload TWO files for every ONE they really want to send.

To keep things simple, a process called MacBinary was developed (thank you
Yves Lempereur).  It combines the two physical files into one.  Consequently,
it also separates a combined file back into two.

Most Macintosh modem programs have MacBinary built in.  The combining and
separating goes on behind the scenes while you are respectively uploading and
downloading.  If you are downloading with a DOS modem program, however 
this step is not automatic.  In fact, it doesn't even exist.  DOS modem program
have no reason to include MacBinary capabilities in their logic.  You, therefore
have to do this manually.

That is why BinHex5 was written.  It will separate the Resource and Data forks
back into two files or combine them into one.



What About BinHex4?
-------------------
BinHex4 was developed for people who must transfer binary data over networks
supporting standard ASCII characters only.  It will take the two physical
parts of a Macintosh binary file, convert them into standard ASCII characters,
then combine them into one physical file.  You can then send or view this file as
a standard text document (although most of it will make little sense) within
environments such as electronic mail.  Once received, it would then have to be
re-translated back into its original file and binary character format.