James Logan said:
# Interactive markets a product called PC-Interface. It works in conjuction with a ms-dos package called DOS Bridge. This package "provides a transparent integration of the DOS and Unix systems". Has anyone used this package? It sounds like it provides all the features of NFS and rlogin rolled into one package. Is this true?

   Yes.  I used it back in '85.  Very nice package back then, it must have improved quite a bit in the past 4 years.  It allowed a DOS user to connect to a server daemon on one or more UNIX host. Each host was assigned its own virtual drive under DOS.

   On the UNIX side, the server that was forked by the daemon would change to your home directory initially, so you wouldn't start writing all over the root partition.  All regular DOS commands worked as usual.  It came with a few DOS commands that imitated "ls" and "chmod" too.  

   The only thing it was lacking at the time was the ability to run a UNIX command from DOS.  Maybe they have added that, I don't know.  It would have been nice to have been able to use a command, like "unix" that ran its arguments as a command. 

Commands like:  C:\> unix mailx would have been useful.  I don't think it would have been that difficult to implement.

   It does work over the serial line as well.  You get a DOS terminal window so you can dial up the host and login as usual, then you invoke an executable, hit a function key on the PC, and you're connected as you would be using TCP/IP, although much slower.

Bruce A. McIntyre wrote:
   I have used PC-Interface with UNIX, NCR Tower, Unisys, and Arix machines. It does provide logical disks on the unix host for the PC machine, and can even re-direct printer output, but dos not provide any other access for the PC to the UNIX host.  However, the unix machine can put files in, or read files from the "logical drive" of the PC, which is nothing more than a login directory for the PC.  IBM resells a version of this for AIX called DOS SERVICES or something like that.  XENIX-NET from SCO provides similar services as well, and I have used that for XENIX.  Both of these also provide somewhat brain damaged terminal emulators, but in fact, PC-FACET supports PC-INTERFACE to allow full windowed terminal emulation etc.

Both are valuable products, and do what they claim quite well,  however,
neither provides what you would expect from a full version of NFS.

Daniel A. Graifer wrote:
   We are using PC-Interface extensively here with our Prime EXL hosts.  It provides the following services to an MS-DOS PC over either any of a large list of ethernet controllers or the com1/2: ports:

Connections to multiple unix hosts simultaneously.
      Each connected host's unix files system appears as as DOS drive letter. Non-DOS acceptable filenames are mapped to unique DOS names with funny  chars.  At the beginning of the connection, the current directory is set to the user's home directory.  It then changes with the dos CD command according to MS DOS rules.  DOS file attributes (ie readonly and modification time) are correctly mapped.

There is a DOS command "on" with syntax like "on [systemname or drive- letter] unixcommand" which will run unix task(s) either synchronously or asynchronously. (ie it recognizes a terminating ampersand) and which accepts input and output redirection.  This works well, and we use it heavily.  Example, we login via a batch file contain a line like: 
        on sysname 'date %T' |time >nul: 
which sets the time clock on the DOS machine to match the unix system's.

There is a printer command which allows you to redirect separately 
LPT1:, LPT2:, LPT3: into any unix command.  The default is set by the host, usually "lp", but we've used things like "tee -a logfile |lp  -dPagePrinter -oLANDSCAPE" very successfully.  This especially useful when using Postscript printers with DOS programs that don't support Postscript...just have a printer interface option to preface the print
 job with a simple postscript lineprinter program.

        There is a slightly braindamaged vt100 terminal emulator program that works over either the ethernet or the serial ports.  Once you have connected to a system, you can pop back and forth between a unix login session and DOS with a function key.  We found it useful to buy SuperKey, a DOS keyboard Macro program, and use it to remap function keys etc used with this program.

     All in, we find it a very useful package.  The version we have (2.8.7) is very painless and reliable.  The "on" command is especially useful within
batch files.  We have DOS users running things on the unix hosts all the time without even knowing that's what's happening.

P.S. You may be curious to know that it use UDP/IP, not TCP for the ethernet communication.  I believe there are efficiency reasons for doing this, but I'm no expert.