PC-NFS Driver Compatibility Kit

                      -------------------------------



1. Introduction



This file describes the PC-NFS Driver Compatibility Kit which you have

received. It contains general information about the use, availability,

and status of this kit. Specific information about the various elements

of the kit is given in the files NDIS and PKTD. In addition, the file MSGS

contains selected email messages about the use of the Packet Driver

interface with the Brigham Young University material to allow PC-NFS

and Novell NetWare to coexist.





2. Rationale



The purpose of this kit is twofold:

- to allow you to use PC-NFS with network adapters for which PC-NFS drivers 

  are not available

- to allow you to run PC-NFS together with other networking software which

  cannot use the PC-NFS drivers



The technique which we use is to create a layer of software "glue"

which makes PC-NFS look like an application which was designed for some

other network driver architecture. The "glue" implements the PC-NFS

LLDK (Link Level Driver Kit) interface at its "top", and the "foreign"

interface at the bottom.





Normally PC-NFS drivers interact as shown here:



   +-----------------------------+

   |     PCNFS.SYS               |

   | (Redirector/NFS/RPC/UDP/IP) |

   +-----------------------------+

           ^       |

           | LLDK  |

           |       v

   +-----------------------------+

   |  PC-NFS Link Level Driver   |

   |    (e.g. WD8003E.SYS)       |

   +-----------------------------+

           ^        |

           |        v

        +------------------|

        | Ethernet hardware|=

        +-----------+......|

                    |||||||







To run over a third-party network interface, we need to arrange things thus:





   +-----------------------------+

   |     PCNFS.SYS               |

   | (Redirector/NFS/RPC/UDP/IP) |

   +-----------------------------+

           ^       |

           | LLDK  |

           |       v

   +-----------------------------+

   |  PC-NFS Link Level Driver   |

   |  "Glue" for interface XXX   |

   +-----------------------------+

           ^       |

           | XXX   |

           |       v

   +-----------------------------+

   |  Ethernet driver XXX        |

   |                             |

   +-----------------------------+

           ^        |

           |        v

        +------------------|

        | Ethernet hardware|=

        +-----------+......|

                    |||||||





The advantage to this arrangement is that the new Ethernet driver may

support hardware that PC-NFS does not; it may also support multiple

applications, as shown below. The disadvantage is that it is likely

to use more memory and be somewhat slower than using a "native" PC-NFS

driver.



   +-----------------------------+

   |     PCNFS.SYS               |

   | (Redirector/NFS/RPC/UDP/IP) |

   +-----------------------------+

           ^       |

           | LLDK  |

           |       v

   +-----------------------------+   +-----------------------------+

   |  PC-NFS Link Level Driver   |   |  Some other network         |

   |  "Glue" for interface XXX   |   |  aplication supporting XXX  |

   +-----------------------------+   +-----------------------------+

           ^       |                         ^       |

           | XXX   |                         |  XXX  |

           |       v                         |       V

          +-------------------------------------------+

          |          Ethernet driver XXX              |

          |                                           |

          +-------------------------------------------+

                     ^        |

                     |        v

                +------------------|

                | Ethernet hardware|=

                +-----------+......|

                            |||||||





This kit includes "glue" (in both binary and source forms) for two popular

network adapter driver designs: the Packet Driver Specification published

by FTP Software, Inc., and the NDIS MAC specification published by 3Com and

Microsoft.



3. Disclaimer



You should note that this software is not an officially supported Sun

Microsystems product. This is because it is our policy to only release

and support software configurations which we can satisfactorily test

and validate.  Since there are many different Packet Drivers and NDIS

drivers in use in the marketplace, we cannot verify the correct

operation of PC-NFS with all, or even a substantial number, of these.

While we are glad to be able to make this software available so that

PC-NFS users can take advantage of hardware and software opportunities

that would otherwise be unattainable, we are unable to warrant or

support these ad hoc configurations.  Users are free to use this

software, fix any bugs or compatibility issues that they may encounter,

and pass these changes to other users. Sun Microsystems reserves the

right to incorporate this software in future releases of the PC-NFS

product, but is not committed to doing so.



4. Availability



The PC-NFS Driver Compatibility Kit is available from the following

sources:



- Via anonymous FTP from Clarkson University (sun.soe.clarkson.edu)

- From the Sun-Spots archive at Rice University

- TBD



5. Status



This memorandum corresponds to version 2.0 of the PC-NFS Driver

Compatibility Kit, as of June 25 1990.



6. Contact



Bug fixes, comments, etc. should be emailed to geoff@East.Sun.COM.

However we cannot guarantee that they will be replied to or acted upon.

Any fixes that are received will be evaluated and, if appropriate,

folded into the next distribution of this kit. [N.b. The code may also

be incorporated into the official PC-NFS release, so anything with

a copyright will be ignored.]